• 제목/요약/키워드: convex points

검색결과 204건 처리시간 0.023초

CAD/CAPP 인터페이스를 위한 형상특징의 자동인식시스템 개발 (Development of Automatic Feature Recognition System for CAD/CAPP Interface)

  • 오수철;조규갑
    • 대한기계학회논문집
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    • 제16권1호
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    • pp.31-40
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    • 1992
  • 본 연구에서는 CAD 시스템의 테이터구조로 부터 특성을 추출하여 CAPP 시스템 의 입력으로 사용되는 형상특징을 자동적으로 인식하고 형상특징의 관련정보를 생성하 는 형상특징인식시스템을 개발하는데 있다. X.Y.Z 축에 수직인 평면들로 구성되는 비회전형상부품을 대상으로 하여, 주로 밀링작업과 연관이 있는 관통슬롯, 막힌슬롯, 관통스텝, 막힌스텝, 포켓의 5가지 형상특징을 자동적으로 인식하는데 특히 X.Y.Z축에 수직인 평면들로 구성되고 내부에 볼록 부위가 업는 형상 특징을 대상으로 한다. CAD시스템은 AutoCAD를 사용하여 퍼스널 컴퓨터에서 시스템을 개발한다.

STRONG CONVERGENCE OF AN ITERATIVE METHOD FOR FINDING COMMON ZEROS OF A FINITE FAMILY OF ACCRETIVE OPERATORS

  • Jung, Jong-Soo
    • 대한수학회논문집
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    • 제24권3호
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    • pp.381-393
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    • 2009
  • Strong convergence theorems on viscosity approximation methods for finding a common zero of a finite family accretive operators are established in a reflexive and strictly Banach space having a uniformly G$\hat{a}$teaux differentiable norm. The main theorems supplement the recent corresponding results of Wong et al. [29] and Zegeye and Shahzad [32] to the viscosity method together with different control conditions. Our results also improve the corresponding results of [9, 16, 18, 19, 25] for finite nonexpansive mappings to the case of finite pseudocontractive mappings.

VISCOSITY APPROXIMATION METHODS FOR NONEXPANSIVE SEMINGROUPS AND MONOTONE MAPPPINGS

  • Zhang, Lijuan
    • East Asian mathematical journal
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    • 제28권5호
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    • pp.597-604
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    • 2012
  • Let C be a nonempty closed convex subset of real Hilbert space H and F = $\{S(t):t{\geq}0\}$ a nonexpansive self-mapping semigroup of C, and $f:C{\rightarrow}C$ is a fixed contractive mapping. Consider the process {$x_n$} : $$\{{x_{n+1}={\beta}_nx_n+(1-{\beta}_n)z_n\\z_n={\alpha}_nf(x_n)+(1-{\alpha}_n)S(t_n)P_C(x_n-r_nAx_n)$$. It is shown that {$x_n$} converges strongly to a common element of the set of fixed points of nonexpansive semigroups and the set of solutions of the variational inequality for an inverse strongly-monotone mapping which solves some variational inequality.

EXTREMAL PROBLEM OF A QUADRATICALLY HYPONORMAL WEIGHTED SHIFT

  • Lee, Hee-Yul;Lee, Mi-Ryeong
    • Journal of applied mathematics & informatics
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    • 제26권3_4호
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    • pp.673-678
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    • 2008
  • Let $W_{\alpha}$, be a recursively generated quadratically hyponormal weighted shift with a weight sequence ${\alpha}$ : 1, (1, $\sqrt{x}$, $\sqrt{y}$)$^{\wedge}$. In [4] Curto-Jung showed that R = {(x,y) : $W_{1,\;(1,\;{\sqrt{x}},\;{\sqrt{y}})^{\wedge}}$ is quadratically hyponormal} is a closed convex with nonempty interior, which guarantees that there are a lot of quadratically hyponormal weighted shifts with first two equal weights. They suggested a problem computing expressions of certain extremal points of R. In this note we obtain a partial answer of their extremal problem.

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ITERATIVE APPROXIMATION OF FIXED POINTS FOR φ-HEMICONTRACTIVE OPERATORS IN BANACH SPACES

  • Liu, Zeqing;An, Zhefu;Li, Yanjuan;Kang, Shin-Min
    • 대한수학회논문집
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    • 제19권1호
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    • pp.63-74
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    • 2004
  • Suppose that X is a real Banach space, K is a nonempty closed convex subset of X and T : $K\;\rightarrow\;K$ is a uniformly continuous ${\phi}$-hemicontractive operator or a Lipschitz ${\phi}-hemicontractive$ operator. In this paper we prove that under certain conditions the three-step iteration methods with errors converge strongly to the unique fixed point of T. Our results extend the corresponding results of Chang [1], Chang et a1. [2], Chidume [3]-[7], Chidume and Osilike [9], Deng [10], Liu and Kang [13], [14], Osilike [15], [16] and Tan and Xu [17].

Some results on metric fixed point theory and open problems

  • Kim, Tae-Hwa;Park, Kyung-Mee
    • 대한수학회논문집
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    • 제11권3호
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    • pp.725-742
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    • 1996
  • In this paper we give some sharp expressions of the weakly convergent sequence coefficient WCS(X) of a Banach space X. They are used to prove fixed point theorems for involution mappings T from a weakly compact convex subset C of a Banach space X with WCS(X) > 1 into itself which $T^2$ are both of asymptotically nonexpansive type and weakly asymptotically regular on C. We also show that if X satisfies the semi-Opial property, then every nonexpansive mapping $T : C \to C$ has a fixed point. Further, some questions for asymtotically nonexpansive mappings are raised.

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NEW HYBRID ALGORITHM FOR WEAK RELATIVELY NONEXPANSIVE MAPPING AND INVERSE-STRONGLY MONOTONE MAPPING IN BANACH SPACE

  • Zhang, Xin;Su, Yongfu;Kang, Jinlong
    • Journal of applied mathematics & informatics
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    • 제29권1_2호
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    • pp.87-102
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    • 2011
  • The purpose of this paper is to prove strong convergence theorems for finding a common element of the set of fixed points of a weak relatively nonexpansive mapping and the set of solutions of the variational inequality for an inverse-strongly-monotone mapping by a new hybrid method in a Banach space. We shall give an example which is weak relatively nonexpansive mapping but not relatively nonexpansive mapping in Banach space $l^2$. Our results improve and extend the corresponding results announced by Ying Liu[Ying Liu, Strong convergence theorem for relatively nonexpansive mapping and inverse-strongly-monotone mapping in a Banach space, Appl. Math. Mech. -Engl. Ed. 30(7)(2009), 925-932] and some others.

CONVERGENCE OF APPROXIMATING PATHS TO SOLUTIONS OF VARIATIONAL INEQUALITIES INVOLVING NON-LIPSCHITZIAN MAPPINGS

  • Jung, Jong-Soo;Sahu, Daya Ram
    • 대한수학회지
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    • 제45권2호
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    • pp.377-392
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    • 2008
  • Let X be a real reflexive Banach space with a uniformly $G\hat{a}teaux$ differentiable norm, C a nonempty closed convex subset of X, T : C $\rightarrow$ X a continuous pseudocontractive mapping, and A : C $\rightarrow$ C a continuous strongly pseudocontractive mapping. We show the existence of a path ${x_t}$ satisfying $x_t=tAx_t+(1- t)Tx_t$, t $\in$ (0,1) and prove that ${x_t}$ converges strongly to a fixed point of T, which solves the variational inequality involving the mapping A. As an application, we give strong convergence of the path ${x_t}$ defined by $x_t=tAx_t+(1-t)(2I-T)x_t$ to a fixed point of firmly pseudocontractive mapping T.

레이저 코너 패턴의 매칭을 이용한 이동 로봇의 EKF 기반 SLAM (EKF-based Simultaneous Localization and Mapping of Mobile Robot using Laser Corner Pattern Matching)

  • 김태형;박태형
    • 전기학회논문지
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    • 제65권12호
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    • pp.2094-2102
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    • 2016
  • In this paper, we propose an extended Kalman filter(EKF)-based simultaneous localization and mapping(SLAM) method using laser corner pattern matching for mobile robots. SLAM is one of the most important problems of mobile robot. However, existing method has the disadvantage of increasing the computation time, depending on the number of landmarks. To improve computation time, we produce the corner pattern using classified and detected corner points. After producing the corner patterns, it is estimated that mobile robot's global position by matching them. The estimated position is used as measurement model in the EKF. To evaluated proposed method, we preformed the experiments in the indoor environments. Experimental results of proposed method are shown to maintain an accuracy and decrease the computation time.

NURBS를 이용한 4절 링크의 자동 경로 생성 (Synthesis of Automatically Path-Generating Four-Bar Linkage Using NURBS)

  • 황득현;앙현익
    • 한국생산제조학회지
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    • 제18권6호
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    • pp.576-584
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    • 2009
  • Up to now, it has been said that no satisfactory computer solution has been found for synthesizing four-bar linkage based on the prescribed coupler link curve. In our study, an algorithm has been developed to improve the design synthesis of four bar linkage based on the 5 precision points method. The suggested algorithm generates the desired coupler curve by using NURBS, and then the generated curve approximates as closely as possible to the desired curve representing coupler link trajectory. Also, when comparing each generated curve by constructing the control polygon, rapid comparison is easily achieved by applying convex hull of the control polygon. Finally, an optimization process using ADS is incorporated into the algorithm based on the 5 precision point method to reduce the total optimization process time. As for examples, two four bar linkages were tested and the result well demonstrated the effectiveness of the algorithm.

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