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무제한 2차원 절단문제에 대해 개선된 최적-우선 분지한계 해법 (An Improved Best-First Branch and Bound Algorithm for Unconstrained Two-Dimensional Cutting Problems)

  • 윤기섭;방성규;강맹규
    • 한국경영과학회지
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    • 제30권4호
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    • pp.61-70
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    • 2005
  • In this Paper, we develop an improved branch and bound algorithm for the (un)weighted unconstrained two-dimensional cutting problem. In the proposed algorithm, we improve the branching strategies of the existing exact algorithm and reduce the size of problem by removing the dominated pieces from the problem. We apply the newly Proposed definition of dominated cutting pattern and it can reduce the number of nodes that must be searched during the algorithm procedure. The efficiency of the proposed algorithm is presented through comparison with the exact algorithm known as the most efficient.

Design of Survivable Communication Networks with High-connectivity Constraints

  • Koh, Seok J.;Lee, Chae Y.
    • 한국경영과학회지
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    • 제22권3호
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    • pp.59-80
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    • 1997
  • Designing highly survivable interoffice telecommunication networks is considered. The problem is formulated as a minimum-cost network design problem with three node connectivity constraints. These valid and facet-defining inequalities for the convex hull of the solution are presented. A branch and cut algorithm is proposed based on the inequalities to obtain the optimal solution. With the lower bound by the cutting plane algorithm, a delete-ink heuristic is proposed to otain a good upper bound in the branch and bound procedure. The effeciveness of the branch and cut algorithm is demonstrated with computational results for a variety of problem sets : different lower bounds, two types of link costs and large number of links. The cutting plane procedure based on the three inequalities provides excellent lower bounds to the optimal solutions.

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Small Non-coding Transfer RNA-Derived RNA Fragments (tRFs): Their Biogenesis, Function and Implication in Human Diseases

  • Fu, Yu;Lee, Inhan;Lee, Yong Sun;Bao, Xiaoyong
    • Genomics & Informatics
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    • 제13권4호
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    • pp.94-101
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    • 2015
  • tRNA-derived RNA fragments (tRFs) are an emerging class of non-coding RNAs (ncRNAs). A growing number of reports have shown that tRFs are not random degradation products but are functional ncRNAs made of specific tRNA cleavage. They play regulatory roles in several biological contexts such as cancer, innate immunity, stress responses, and neurological disorders. In this review, we summarize the biogenesis and functions of tRFs.

형태제약을 가지는 부서의 다층빌딩 설비배치 (Multi-level Building Layout With Dimension Constraints On Departments)

  • Chae-Bogk Kim
    • 산업경영시스템학회지
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    • 제26권4호
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    • pp.42-49
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    • 2003
  • The branch and bound techniques based on cut tree and eigenvector have been Introduced in the literature [1, 2, 3, 6, 9, 12]. These techniques are used as a basis to allocate departments to floors and then to fit departments with unchangeable dimensions into floors. Grouping algorithms to allocate departments to each floor are developed and branch and bound forms the basis of optimizing using the criteria of rectilinear distance. The proposed branch and bound technique, in theory, will provide the optimal solution on two dimensional layout. If the runs are time and/or node limited, the proposed method is a strong heuristic The technique is made further practical by the fact that the solution is constrained such that the rectangular shape dimensions length and width are fixed and a perfect fit is generated if a fit is possible. Computational results obtained by cut tree-based algorithm and eigenvector-based algorithm are shown when the number of floors are two or three and there is an elevator.

다중기계로 구성되는 조립전단계에서의 부품생산 일정계획 (Scheduling on the Pre-assembly Stage of Multiple Fabrication Machines)

  • 윤상흠
    • 산업경영시스템학회지
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    • 제26권4호
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    • pp.63-71
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    • 2003
  • This paper analyses a deterministic scheduling problem concerned with manufacturing multiple types of components at a pre-assembly stage composed of parallel fabrication machines. Each component part is machined on a fabrication machine specified in advance. The manufactured components are subsequently assembled into products. The completion time of a job(product) is measured by the latest completion time of its all components at the pre-assembly stage. The problem has the objective measure of minimizing the total weighted completion time of a finite number of jobs. Two lower bounds are derived and tested in a branch-and-bound scheme. Also, three constructive heuristic algorithms are developed based on the machine aggregation and greedy strategies. Some empirical evaluation of the performance of the proposed branch-and-bound and heuristic algorithms are also performed.

An Improved Branch-and-Bound Algorithm for Scheduling Jobs on Identical Machines

  • Park, Sung-Hyun
    • 대한산업공학회지
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    • 제1권2호
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    • pp.73-81
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    • 1975
  • In an earlier paper ('Scheduling Jobs on a Number of Identical Machines' by Elmaghraby and Park, March 1974, AIIE Transactions) a branch-and-bound algorithm was developed for the sequencing problem when all jobs are available to process at time zero and are independet (i.e., there are not a priori precedence relationships among jobs.). However, the amount of computation required by the algorithm was not considered to be short if more than 50 jobs were processed. As an effort to improve the algorithm, the present paper modifies the implicit enumeration procedure in the algorithm so that moderately large problems can be treated with what appears to be a short computational time. Mainly this paper is concerned with improving the lower bound in the implicit enumeration procedure. The computational experiences with this new branch-and-bound algorithm are given.

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풍력발전시스템의 배전선로 전압 영향분석 (Distribution Line Voltage Impact Analysis of Wind Power Generation System)

  • 나경윤;고성민;김세호;이수묵;신삼균;김문찬
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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    • pp.1759-1761
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    • 2005
  • The exploitation of the resource wind energy is a rapidly growing area world-wide. The number of installed units is continuously increasing, and therefore, it is important to respect and to deal with the impact of wind power generation system. From the view of an electric grid utility, there is a major problem with the impact of the wind system on the voltage of the electric grid, to which a turbine in connected. The problem is rather common in the connection of a wind power system to an already existing grid, since the grid is very seldom designed for the transmission of additional power. In this paper, it is investigated the voltage impact of distribution line, to which wind power generation system is connected.

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민간약 오리나무의 생약학적 연구 (Pharmacognostical Studies on the Korean Folk Medicine "ORiNaMu")

  • 이창훈;김성룡;배지영;박종희
    • 생약학회지
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    • 제42권3호
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    • pp.209-212
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    • 2011
  • Korean folk medicine 'ORiNaMu' has been used mainly to cure toothache and alcoholism. With regard to the botanical origin of 'ORiNaMu', it has been considered to designate the branch of Alnus species (Betulaceae), but there was no pharmacognostical confirmation on it. To clarify the botanical origin of 'ORiNaMu', the anatomical characteristics of the branch of Alnus firma, A. hirsuta, A. japonica and A. maximowiczii were studied. As a result, it was found the morphological criteria for the four Alnus species that could discriminate them the number of cork cell layer, fiber, stone cell and diameter of vessel. According to there criteria, it was clarified that the commercial folk medicine 'ORiNaMu' was the branch of Alnus firma.

Coherent motion of microwave-induced fluxons in intrinsic Josephson junctions of HgI$_2$-intercalated Bi$_2$Sr$_2$C aCu$_2$O$_{8+x}$ single crystals

  • Kim, Jin-Hee;Doh, Yong-Joo;Chang, Sung-Ho;Lee, Hu-Jong;Chang, Hyun-Sik;Kim, Kyu-Tae;Jang, Eue-Soon;Choy, Jin-Ho
    • 한국초전도학회:학술대회논문집
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    • 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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    • pp.65-65
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    • 2000
  • Microwave response of intrinsic Josephson junctions in mesa structure formed on HgI2-intercalated Bi2Sr2CaCu2O8+x single crystals was studied in a wide range of microwave frequency. With irradiation of 73${\sim}$76 GHz microwave, the supercurrent branch becomes resistive above a certain onset microwave power. At low current bias, the current-voltage characteristics show linear behavior, while at high current bias, the resistive branch splits into multiple sub-branches. The voltage spacing between neighboring sub-branches increase with the microwave power and the total number of sub-branches is almost identical to the number of intrinsic Josephson junctions in the mesa. All the experimental results suggest that each sub-branch represents a specific mode of collective motion of Josephson vortices generated by the microwave irradiation. With irradiation of microwave of microwave of frequency lower than 20 GHz, on the other hand, no branch splitting was observed and the current-voltage characteristics exhibited complex behavior at hlgh blas currents. This result can be explained in terms of incoherent motion of Josephson vortices generated by non-uniform microwave irradiation.

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BTB를 이용한 프로세서 기반 멀티미디어 응용 SoC 설계 (A Design of Multimedia Application SoC based with Processor using BTB)

  • 정윤진;이병엽;류광기
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2009년도 추계학술대회
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    • pp.397-400
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    • 2009
  • 본 논문에서는 멀티미디어 어플리케이션을 위한 BTB(Branch Target Buffer)를 이용한 RISC 프로세서 기반 SoC 플랫폼의 ASIC 설계에 대해 기술한다. 제안된 SoC 플랫폼은 성능 개선을 위해 BTB를 포함하며 분기 명령어 패치 시 분기할 타깃 주소를 BTB에 저장함으로써 예측 주소의 명령어를 미리 패치, 파이프라인의 지연을 최소화하였다. 또한, 다양한 멀티미디어 어플리케이션을 위해 VGA 제어기, AC97 제어기, UART 제어기, SRAM 인터페이스, 디버그 인터페이스를 포함한다. 구현된 플랫폼은 다양한 테스트 프로그램을 사용하여 시뮬레이션을 수행하였으며, Xilinx VIRTEX-4 XC4VLX80 FPGA를 이용해 기능 및 타이밍 검증을 수행하였다. 최종적으로 Chartered 0.18um 공정을 이용하여 단일 ASIC 칩으로 구현되었으며 100MHz에서 정상 동작함을 확인하였고, 이전 OpenRISC 마이크로프로세서를 사용한 플랫폼과의 비교를 위해 산술연산 및 AC97 테스트 프로그램을 이용한 시뮬레이션 결과 5~9%의 성능향상을 확인하였다.

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