• 제목/요약/키워드: convex function

검색결과 446건 처리시간 0.035초

통행배정과 신호제어 결합문제를 풀기위한 새로운 해법 개발에 관한 연구 (A Simulated Annealing Method for Solving Combined Traffic Assignment and Signal Control Problem)

  • 이승재
    • 대한교통학회지
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    • 제16권1호
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    • pp.151-164
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    • 1998
  • 본 논문은 통행배정과 교통신호제어기의 결합문제를 풀기 위한 새로운 해법의 제시를 목적으로 한다. 통행배정과 신호제어 결합모형은 네트웍 디자인 문제(Network Design Problem)로 비선형 비분리 목적함수(Nonlinear and Nonseparable Objective Function)와 비선형제약 및 비컴백스 집합(Nonlinear and Non-Convex Set)형태로 인해 다수의 국지해(Multiple Local Optima)를 갖는 특징이 있다. 따라서 이렇게 복잡하고 난해한 문제를 푸는 해법은 많은 국지해중에 가장 최소한 값(Global Optima)을 찾을수 있는 방법을 제공하여야한다. 전체최적해(Global Optima)를 찾 을 수 있는 기존의 방법들은 확률적최적화방법(Stochastic Optimization Methods)에 속한다. 본연구에서는 이러한 방법중 금속공학에서 발 견된 모의담금빌법(Simulated Annealing Method)에 근거한 해법을 제시한다. 이방법이 통행배정과 신호제어 결합문제에 적용되는지 검토하기 위해 이해법의 수렴성(Convergence)을 증명했으며 또한 실제 프로그램된 모형을 작은 고안된 네트워크에 적 용했다. 마지막으로는 개발된 해법의 실용성을 실험하기 위해 두 가지의 보다 큰 도로망에 적용 및 분석을 했다.

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이산형 적흑게임에서 유리한 경우의 최적전략 (The Optimum Strategy for Favorable Situation in Discrete Red & Black)

  • 석영우;안철환
    • 한국국방경영분석학회지
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    • 제30권1호
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    • pp.70-80
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    • 2004
  • In discrete red and black, you can stake any amount s in your possession, but the value of s takes positive integer value. Suppose your goal is N and your current fortune is f, with 0<f<N. You win back your stake and as much more with probability p and lose your stake with probability, q = 1-p. In this study, we consider optimum strategies for this game with the value of p greater than $\frac{1}{2}$ where the player has the advantage over the house. The optimum strategy at any f when p>$\frac{1}{2}$ is to play timidly, which is to bet 1 all the time. This is called as Timid1 strategy. In this paper, we perform the simulation study to show that the Timid1 strategy is optimum in discrete red and black when p>\frac{1}{2}.

뱀형 로봇에 대한 이동궤적과 장애물 회피 시뮬레이션 (Locomotion of Snake Robot and Obstacle Avoidance Simulation)

  • 이지우;이창훈;김용호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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    • pp.3-6
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    • 2003
  • 뱀형 로봇은 일반적인 바퀴형 이동로봇과 운동 메카니즘이 상이하며 다관절로 이루어져 있기 때문에 장애물 회피에 있어 빠른 정보의 처리와 이를 위한 특별한 정보가 요구된다. 이를 실현하기 위하여 로봇은 자신의 위치를 지속적으로 파악하면서 장애물의 좌표 값과 일정한 거리의 간격을 두고 움직여야 한다. 주행 궤도 및 장애물 회피를 위한 알고리즘을 검증하기 위하여 가상 뱀형 시뮬레이터를 제작하였다. 시뮬레이터는 이동 주행 궤도를 생성하고, 지나온 궤도를 재현할 수 있는 재현기(Back Tracker), 앞으로 이루어질 뱀형 로봇의 위치와 자세를 알아보는 예견기(Predictor)로 구성된다. 시뮬레이터를 통하여 주위의 장애물을 안전하게 통과할 수 있는 일반적인 알고리즘인 포텐셜함수의 특성을 알아보고, 국소 최소점(Local Minima)에 빠지기 쉬운 단점을 극복하기 위한 방안을 제시한다. 본 논문에서는 뱀의 이동 주행 궤적을 알아보고, 주위의 장애물을 안전하게 통과할 수 있도록 하는 알고리즘에 대한 고찰과 제안한 알고리즘을 소프트웨어적인 3D 시뮬레이션을 통하여 걸과를 분석하고 검증한다.

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CHARACTERIZATIONS OF GEOMETRICAL PROPERTIES OF BANACH SPACES USING ψ-DIRECT SUMS

  • Zhang, Zhihua;Shu, Lan;Zheng, Jun;Yang, Yuling
    • 대한수학회보
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    • 제50권2호
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    • pp.417-430
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    • 2013
  • Let X be a Banach space and ${\psi}$ a continuous convex function on ${\Delta}_{K+1}$ satisfying certain conditions. Let $(X{\bigoplus}X{\bigoplus}{\cdots}{\bigoplus}X)_{\psi}$ be the ${\psi}$-direct sum of X. In this paper, we characterize the K strict convexity, K uniform convexity and uniform non-$l^N_1$-ness of Banach spaces using ${\psi}$-direct sums.

시변지연을 가지는 TS퍼지시스템을 위한 견실 시간종속 안정성판별법 (Robust Delay-dependent Stability Criteria for Takagi-Sugeno Fuzzy Systems with Time-varying Delay)

  • 유아연;이상문;권오민
    • 전기학회논문지
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    • 제64권6호
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    • pp.891-899
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    • 2015
  • This paper presents the robust stability condition of uncertain Takagi-Sugeno(T-S) fuzzy systems with time-varying delay. New augmented Lyapunov-Krasovskii function is constructed to ensure that the system with time-varying delay is globally asymptotically stable. Also, less conservative delay-dependent stability criteria are obtained by employing some integral inequality, reciprocally convex approach and new delay-partitioning method. Finally, two numerical examples are provided to demonstrate the effectiveness of the proposed method.

복수제품의 선별검사 및 서비스시스템의 설계 (A Joint Design of Rectifying Inspection Plans and Service Capacities for Multi-Products)

  • 김성철
    • 한국경영과학회지
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    • 제35권1호
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    • pp.97-109
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    • 2010
  • In this paper, we study a joint design problem of sampling inspections and service capacities for multi-products. Products are supplied in batches after rectifying inspections, that is, rejected lots are 100% inspected and defective products are reworked to good ones. When supplied, all defective products are uncovered through total inspection and returned to service. By exploiting the first and second order properties of the objective function, we identify the optimal inspection policies and service capacities for individual products, and develop allocation algorithms to obtain an optimal allocation of the limited total service capacity to products with the small number of computations.

루에 동적 시스템을 위한 샘플데이타 제어 (Sampled-data Control for Lur'e Dynamical Systems)

  • 유아연;이상문
    • 전기학회논문지
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    • 제63권2호
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    • pp.261-265
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    • 2014
  • This paper studies the problem of the sampled-data control for Lur'e system with nonlinearities. The nonlinearities are expressed as convex combinations of sector and slope bounds. It is assumed that the sampling periods are arbitrarily varying but bounded. By constructing a new augmented Lyapunov-Krasovskii functional which have an augmented quadratic form with states as well as the nonlinear function, the stabilizing sampled-data controller gains are obtained by solving a set of linear matrix inequalities. The effectiveness of the developed method is demonstrated by numerical simulations.

혼류 생산시스템의 주기적 생산순서 (Cyclic Sequencing in Mixed-Model Production Systems)

  • 최원준;김연민;박창권;이용일
    • 대한산업공학회지
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    • 제30권4호
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    • pp.317-327
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    • 2004
  • In mixed-model production systems, various models of products are produced alternately on the same production line. When the total number of models or the total production quantity is large, it takes a long time to determine the production sequence of the products. In this paper, we will show that in case of product rate variation problem (PRV) problem with nonidentical symmetric convex discrepancy function, an optimum sequence can be obtained by repeating an optimum sequence in a reduced subproblem.

SOME GEOMERTIC SOLVABILITY THEOREMS IN TOPOLOGICAL VECTOR SPACES

  • Ben-El-Mechaiekh, H.;Isac, G.
    • 대한수학회보
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    • 제34권2호
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    • pp.273-285
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    • 1997
  • The aim of this paper is to present theorems on the exitence of zeros for mappings defined on convex subsets of topological vector spaces with values in a vector space. In addition to natural assumptions of continuity, convexity, and compactness, the mappings are subject to some geometric conditions. In the first theorem, the mapping satisfies a "Darboux-type" property expressed in terms of an auxiliary numerical function. Typically, this functions is, in this case, related to an order structure on the target space. We derive an existence theorem for "obtuse" quasiconvex mappings with values in an ordered vector space. In the second theorem, we prove the existence of a "common zero" for an arbitrary (not necessarily countable) family of mappings satisfying a general "inwardness" condition againg expressed in terms of numerical functions (these numerical functions could be duality pairings (more generally, bilinear forms)). Our inwardness condition encompasses classical inwardness conditions of Leray-Schauder, Altman, or Bergman-Halpern types.

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ON SOME DIFFERENTIAL SUBORDINATION INVOLVING THE BESSEL-STRUVE KERNEL FUNCTION

  • Al-Dhuain, Mohammed;Mondal, Saiful R.
    • 대한수학회논문집
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    • 제33권2호
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    • pp.445-458
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    • 2018
  • In this article we study the inclusion properties of the Bessel-Struve kernel functions in the Janowski class. In particular, we find the conditions for which the Bessel-Struve kernel functions maps the unit disk to right half plane. Some open problems with this aspect are also given. The third order differential subordination involving the Bessel-Struve kernel is also considered. The results are derived by defining suitable classes of admissible functions. One of the recurrence relation of the Bessel-Struve kernel play an important role to derive the main results.