• 제목/요약/키워드: linear operator.

검색결과 501건 처리시간 0.055초

퍼지이론을 이용한 CNC 공작기계의 절삭력제어 (Cutting Force Control of a CNC Machine Using Fuzzy Theory)

  • 노상현;이상규;박운환;임윤규
    • 한국산업융합학회 논문집
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    • 제3권2호
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    • pp.123-130
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    • 2000
  • Fuzzy control is proposed to regulate cutting force in turning operations under varying cutting conditions. The traditional linear controllers based on crisp mathematical model cannot effectively control cutting force becasue of the nonlinear dynamics of turning operations. The proposed fuzzy controller is based on operator experience and expert knowledge. The membership functions for the inputs and the output of the controller are designed. Cutting force is regulated by adjusting feedrate according to the variation of cutting conditions. The performance of the proposed controller is evaluated by experiments. The results of experiments show that the proposed fuzzy controller has a good cutting force regulation over a wide range of cutting conditions.

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QUANTUM EXTENSIONS OF FOURIER-GAUSS AND FOURIER-MEHLER TRANSFORMS

  • Ji, Un-Cig
    • 대한수학회지
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    • 제45권6호
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    • pp.1785-1801
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    • 2008
  • Noncommutative extensions of the Gross and Beltrami Laplacians, called the quantum Gross Laplacian and the quantum Beltrami Laplacian, resp., are introduced and their basic properties are studied. As noncommutative extensions of the Fourier-Gauss and Fourier-Mehler transforms, we introduce the quantum Fourier-Gauss and quantum Fourier- Mehler transforms. The infinitesimal generators of all differentiable one parameter groups induced by the quantum Fourier-Gauss transform are linear combinations of the quantum Gross Laplacian and quantum Beltrami Laplacian. A characterization of the quantum Fourier-Mehler transform is studied.

STRICT TOPOLOGIES AND OPERATORS ON SPACES OF VECTOR-VALUED CONTINUOUS FUNCTIONS

  • Nowak, Marian
    • 대한수학회지
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    • 제52권1호
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    • pp.177-190
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    • 2015
  • Let X be a completely regular Hausdorff space, and E and F be Banach spaces. Let $C_{rc}(X,E)$ be the Banach space of all continuous functions $f:X{\rightarrow}E$ such that f(X) is a relatively compact set in E. We establish an integral representation theorem for bounded linear operators $T:C_{rc}(X,E){\rightarrow}F$. We characterize continuous operators from $C_{rc}(X,E)$, provided with the strict topologies ${\beta}_z(X,E)$ ($z={\sigma},{\tau}$) to F, in terms of their representing operator-valued measures.

WEYL TYPE-THEOREMS FOR DIRECT SUMS

  • Berkani, Mohammed;Zariouh, Hassan
    • 대한수학회보
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    • 제49권5호
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    • pp.1027-1040
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    • 2012
  • The aim of this paper is to study the Weyl type-theorems for the orthogonal direct sum $S{\oplus}T$, where S and T are bounded linear operators acting on a Banach space X. Among other results, we prove that if both T and S possesses property ($gb$) and if ${\Pi}(T){\subset}{\sigma}_a(S)$, ${\PI}(S){\subset}{\sigma}_a(T)$, then $S{\oplus}T$ possesses property ($gb$) if and only if ${\sigma}_{SBF^-_+}(S{\oplus}T)={\sigma}_{SBF^-_+}(S){\cup}{\sigma}_{SBF^-_+}(T)$. Moreover, we prove that if T and S both satisfies generalized Browder's theorem, then $S{\oplus}T$ satis es generalized Browder's theorem if and only if ${\sigma}_{BW}(S{\oplus}T)={\sigma}_{BW}(S){\cup}{\sigma}_{BW}(T)$.

퍼지 논리를 이용한 Subpixel 정확도 Edge 검출 (Edge detection at subpixel accuracy using fuzzy logic)

  • 김영욱;양우석
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.105-108
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    • 1996
  • In this paper, we present an interpolation schema for image resolution enhancement using fuzzy logic. Proposed algorithm can recover both low and high frequency information in image data. In general, interpolation techniques are based on linear operators which are essentially details in the original image. In our fuzzy approach, the operator itself balances the strength of its sharpening and noise suppressing components according to the properties of the input image data. The proposed interpolation algorithm is performed in three step. First logic reasoning is applied to coarsely interpret the high frequency information. These results are combined to obtain the optical output. Using our approach, resolution of the original image can be applied to various kind of image processing topics such as image enhancement, subpixel edge detection, and filtering.

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Line Fitting 을 이용한 삼차원 형상복원 (3D Shape Recovery using Line Fitting)

  • 심성오;아미르;최태선
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.905-906
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    • 2008
  • This paper presents a method where the best focues points are calculated using line fitting. Two datasets are selected for each pixel based on the maximum value which is calculated using Laplacian operator. Then linear regression model is used to find lines that approximate these datasets. The best fit lines are found using least squares method. After approximating the two lines, their intersection point is calculated and weights are assigned to calculate the new value for the depth map.

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디지탈 신호처리용 고정 소수점 최적화 유틸리티 (Fixed-point optimization utility for digital signal processing programs)

  • 김시현;성원용
    • 전자공학회논문지C
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    • 제34C권9호
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    • pp.33-42
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    • 1997
  • Fixed-point optimization utility software that can aid scaling and wordlength determination of digital signal processign algorithms written in C or C$\^$++/ language is developed. This utility consists of two programs: the range estimator and the fixed-point simulator. The former estimates the ranges of floating-point variables for automatic scaling purpose, and the latter translates floating-point programs into fixed-point equivalents for evaluating te fixed-point performance by simulation. By exploiting the operator overloading characteristics of C$\^$++/ language, the range estimation and the fixed-point simulation can be conducted just by modifying the variable declaration of the original program. This utility is easily applicable to nearly all types of digital signal processing programs including non-linear, time-varying, multi-rate, and multi-dimensional signal processing algorithms. In addition, this software can be used for comparing the fixed-point characteristics of different implementation architectures.

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정자계를 가한 반도체를 갖는 도파관내의 전자파이동에 관한 연구 (A Study of Perturbed Electromagnetic Waves in Rectangular Waveguide Filled with atransversely magnetized Semiconductor)

  • 양인응;진연강
    • 대한전자공학회논문지
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    • 제11권2호
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    • pp.12-21
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    • 1974
  • 전자력학적 근사해법인 섭운이론을 횡정식계를 가한 N형 Silicon 반도체로 충만된 거형도파관내의 마이크로로파의 정변특성에 적용해서 전력의 식을 구했다. 이는 전자파의 Maxwell 방정식을 연산자에 의한 고유치문제로 다루어 개발했다. 특히 2개의 Magic-Tee를 사용해서 x만에 의해서 변화하는 전자성분을 검출한 9.61GHz의 TE 파에 의한 실험결과는 제1차사치와 아주 잘 일치했다.

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CONVERGENCE AND STABILITY OF THREE-STEP ITERATIVE SCHEME WITH ERRORS FOR COMPLETELY GENERALIZED STRONGLY NONLINEAR QUASIVARIATIONAL INEQUALITIES

  • ZHANG FENGRONG;GAO HAIYAN;LIU ZEQING;KANG SHIN MIN
    • Journal of applied mathematics & informatics
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    • 제20권1_2호
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    • pp.465-478
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    • 2006
  • In this paper, we introduce a new class of completely generalized strongly nonlinear quasivariational inequalities and establish its equivalence with a class of fixed point problems by using the resolvent operator technique. Utilizing this equivalence, we develop a three-step iterative scheme with errors, obtain a few existence theorems of solutions for the completely generalized non-linear strongly quasivariational inequality involving relaxed monotone, relaxed Lipschitz, strongly monotone and generalized pseudocontractive mappings and prove some convergence and stability results of the sequence generated by the three-step iterative scheme with errors. Our results include several previously known results as special cases.

퍼지 추론을 이용한 비선형 영상 보간 (Nonlinear Interpolation of Images using fuzzy inference)

  • 강금부;이종수;양우석
    • 전기전자학회논문지
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    • 제3권2호
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    • pp.168-177
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    • 1999
  • 이 논문은 디지털 영상에 대한 에지를 보존하는 새로운 영상 보간 방법을 제안한다. 일반적인 보간 기법은 선형 연산자를 이용한 저역필터를 사용함으로써 원 영상의 고조파 성분에 대한 정보를 손실하는바 high contrast 에지 부분에서 희뿌옇게 되는 현상과 톱니현상이 일어나 영상 선명도가 떨어지는 경향이 있었다. 본 논문에서는 이러한 단점을 개선한 새로운 보간 기법을 제시한다. 본 논문에서 제시한 보간 알고리즘은 퍼지 연산자를 이용하여 입력 영상 데이터의 성질에 따라 고주파 성분과 저주파 성분을 달리 조절함으로써 원래 영상에 가까운 해상도를 얻을 수 있다.

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