• Title/Summary/Keyword: Combinatorial

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An Efficient Synthesis of α-Amino-δ-valerolactones by the Ugi Five-Center Three-Component Reaction

  • Kim, Young-Bae;Park, Soo-Jung;Geum, Gyo-Chang;Jang, Min-Seok;Kang, Soon-Bang;Lee, Duck-Hyung;Kim, You-Seung
    • Bulletin of the Korean Chemical Society
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    • v.23 no.9
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    • pp.1277-1320
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    • 2002
  • A novel approach to ${\alpha}-amino-{\delta}-valerolactone$ derivatives 8 by the intramolecular Ugi five-center three-component reaction (U-5C-3CR) using the multifunctional starting material, L-pentahomoserine 5 is described.

Activity of a Gifted Student Who Found Linear Algebraic Solution of Blackout Puzzle

  • Lee, Sang-Gu;Park, Jong-Bin;Yang, Jeong-Mo
    • Research in Mathematical Education
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    • v.8 no.3
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    • pp.215-226
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    • 2004
  • The purpose of this paper is to introduce an activity of student who found purely linear algebraic solution of the Blackout puzzle. It shows how we can help and work with gifted students. It deals with algorithm, mathematical modeling, optimal solution and software.

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A Formulation of Hybrid Algorithm for Linear Programming

  • Kim, Koon-Chan
    • Journal of the Korean Operations Research and Management Science Society
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    • v.19 no.3
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    • pp.187-201
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    • 1994
  • This paper introduces an effective hybridization of the usual simplex method and an interior point method in the convergent framework of Dembo and Sahi. We formulate a specific and detailed algorithm (HYBRID) and report the results of some preliminary testing on small dense problems for its viability. By piercing through the feasible region, the newly developed hybrid algorithm avoids the combinatorial structure of linear programs, and several other interesting and important characteristics of this algorithm are also discussed.

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A Survey on Network Survivability Models (네트워크 생존도 모형 개관)

  • Myung, Young-Soo
    • Journal of Korean Institute of Industrial Engineers
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    • v.34 no.2
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    • pp.181-189
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    • 2008
  • Survivability of a network is one of the most important issues in designing present-day communication networks. For the past few decades, a lot of researches have proposed the mathematical models to evaluate the survivability of networks. In this paper, we attempt to survey such researches and classify them based on how these researches measure the survivability of a network.

PRODUCTS ON THE CHOW RINGS FOR TORIC VARIETIES

  • Park, Hye-Sook
    • Journal of the Korean Mathematical Society
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    • v.33 no.3
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    • pp.469-479
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    • 1996
  • Toric variety is a normal algebraic variety containing algebraic torus $T_N$ as an open dense subset with an algebraic action of $T_N$ which is an extension of the group law of $T_N$. A toric variety can be described in terms of a certain collection, which is called a fan, of cones. From this fact, the properties of a toric variety have strong connection with the combinatorial structure of the corresponding fan and the relations among the generators. That is, we can translate the diffcult algebrogeometric properties of toric varieties into very simple properties about the combinatorics of cones in affine spaces over the reals.

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A Re-Configuration Genetic Algorithm for Distribution Systems (배전계통에서 유전적 알고리즘을 이용한 접속변경순서 결정방법)

  • Choi, Dai-Seub
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2004.11a
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    • pp.381-383
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    • 2004
  • Recently, sectionalizing switches have been coming to be operated by remote control through the distribution SCADA system. However, the problem of determining the optimal switching sequence is a combinatorial optimization problem, and is quite difficult to solve. Hence, it is imperative to develop practically applicable solution algorithms create a new arbitral distribution system configuration from an initial configuration, and some of these algorithms do not show a load transfer sequence to reach the objective system.

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A Re-Configuration Genetic Algorithm for Distribution Systems (배전계통에서 유전적 알고리즘을 이용한 접속변경순서결정방법)

  • Choi, Dai-Seub
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2005.05a
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    • pp.418-420
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    • 2005
  • Recently, sectionalizing switches have been coming to be operated by remote control through the distribution SCADA system. However, the problem of determining the optimal switching sequence is a combinatorial optimization problem, and is quite difficult In solve. Hence, it is imperative to develop practically applicable solution algorithms create a new arbitral distribution system configuration from an initial configuration and some of these algorithms do not show a load transfer sequence to reach the objective system.

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Network Enlarging Search Technique (NEST) for the Crew Scheduling Problem

  • Paek, Gwan-Ho
    • Journal of the Korean Operations Research and Management Science Society
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    • v.19 no.2
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    • pp.177-198
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    • 1994
  • We consider an algorithm for the Crew Scheduling Problem (CSP) based on the Transportation Problem approach. The main flows of the algorithm are arranged in three steps. First we propose a heuristic algorithm of the greedy principle to obtain an initial feasible solution. Secondary we present a method of formulating CSP into a Modified Transportation Problem format. Lastly the procedures of network search to get the optimal solution are presented. This algorithm can be applied to the general GSP and also to most combinatorial problems like the Vehicle Routing Problems. The computational results show that the large size CSP's could be tackled.

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