• Title/Summary/Keyword: Set operations

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A Scheduling Strategy for Reducing Set-up Time and Work-In-Process in PCB Assembly Line (PCB조립 라인의 준비 시간 단축 및 재공품 감소를 위한 스케줄링 전략)

  • 이영해;김덕한;전성진
    • Journal of the Korean Operations Research and Management Science Society
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    • v.22 no.1
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    • pp.25-49
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    • 1997
  • Printed circuit board (PCB) assembly line configuration is characterized by very long set-up times and high work in process (WIP) inventory level. The scheduling method can significantly reduce the set-up times and WIP inventory level. Greedy sequence dependent scheduling (GSDS) method is proposed based on the current methods. The proposed method is compared with the current method in terms of three performance measures: line throughput, average WIP inventory level, and implementation complexity.

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Determination of Arc Candidate Set for the Asymmetric Traveling Salesman Problem (비대칭 외판원문제에서 호의 후보집합 결정)

  • 김헌태;권상호;지영근;강맹규
    • Journal of the Korean Operations Research and Management Science Society
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    • v.28 no.2
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    • pp.129-138
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    • 2003
  • The traveling salesman problem (TSP) is an NP-hard problem. As the number of nodes increases, it takes a lot of time to find an optimal solution. Instead of considering all arcs, if we select and consider only some arcs more likely to be included in an optimal solution, we can find efficiently an optimal solution. Arc candidate set is a group of some good arcs. For the Lack of study in the asymmetric TSP. it needs to research arc candidate set for the asymmetric TSP systematically. In this paper, we suggest a regression function determining arc candidate set for the asymmetric TSP. We established the function based on 2100 experiments, and we proved the goodness of fit for the model through various 787problems. The result showed that the optimal solutions obtained from our arc candidate set are equal to the ones of original problems. We expect that this function would be very useful to reduce the complexity of TSP.

Generalized Intuitionistic Fuzzy Soft Sets

  • Park, Jin-Han;Kwun, Young-Chel;Hwang, Jin-Soo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.3
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    • pp.389-394
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    • 2011
  • The notion of generalized intuitionistic fuzzy soft set theory is proposed. Our generalized intuitionistic fuzzy soft set theory is a combination of the generalized intuitionistic fuzzy set theory and the soft set theory. In other words, our generalized intuitionistic fuzzy soft set theory is an extension of the intuitionistic fuzzy soft set theory. The complement, "and" and "or" operations are defined on the generalized intuitionistic fuzzy soft sets. Their basic properties for the generalized intuitionistic fuzzy soft sets are also presented and discussed.

Flood Season Reservoir Operations Considering Water Supply Objective (용수공급을 고려한 홍수기 저수지 운영방안)

  • Lee, Seung-Hyeon;Kim, Young-Oh
    • Journal of Korea Water Resources Association
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    • v.35 no.6
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    • pp.639-650
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    • 2002
  • Reservoir operations during the flood season should consider both the flood control and water supply objectives. This study proposed Set Control Algorithm (SCA) as a reservoir operation method, which guarantees both objectives. The concept behind SCA is to provide operators with a set of actions that guarantee feasibility, given a set of operational constraints, and to let them select decisions within a set that satisfies other considerations. The inflow sets used in this study included; observed data, synthetic data, and ESP(Ensemble Streamflow Prediction) scenarios. Applied to the Chungju Dam operations, SCA was compared to the variable flood restricted elevation, as well as the current flood restricted elevation. A 5-year simulation analysis showed that SCA performed better than the other operation methods, and that SCA coupled with ESP performed best among the SCA cases.

Dynamic Control for FMS That Has Unreliable Machines with Set-up (기계고장과 Set-up 을 고려한 FMS 의 동적 통제)

  • 엄완섭;강석호
    • Journal of the Korean Operations Research and Management Science Society
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    • v.17 no.1
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    • pp.43-54
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    • 1992
  • This paper discusses a real time production control system of a FMS (Flexible Manufacturing System). The control is organized in a hierarchical structure according to the various decisions at the different time scales. In the earlier work-set-up time was not considered. Because the capacity of the toll magazine is limited, this assumption may not be adequate for selecting times to change configurations so that new part family can be produced. The goal of the control system is to meet production requirements while the machines fail and are repaired at random times. In this thesis the machien failure and set-up are considered simultaneously. Here the hedging point of this system is calculated, and the formulation of the dynamic control for FMS that has unreliable machines with set-up suggested.

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An Empirical Study for Satisfiability Problems in Propositional Logic Using Set Covering Formulation (집합 피복 공식화를 이용한 명제논리의 만족도 문제에 대한 계산실험 연구)

  • Cho, geon
    • Journal of the Korean Operations Research and Management Science Society
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    • v.27 no.4
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    • pp.87-109
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    • 2002
  • A satisfiability problem in propositional logic is the problem of checking for the existence of a set of truth values of atomic prepositions that renders an input propositional formula true. This paper describes an empirical investigation of a particular integer programming approach, using the set covering model, to solve satisfiability problems. Our satisfiability engine, SETSAT, is a fully integrated, linear programming based, branch and bound method using various symbolic routines for the reduction of the logic formulas. SETSAT has been implemented in the integer programming shell MINTO which, in turn, uses the CPLEX linear programming system. The logic processing routines were written in C and integrated into the MINTO functions. The experiments were conducted on a benchmark set of satisfiability problems that were compiled at the University of Ulm in Germany. The computational results indicate that our approach is competitive with the state of the art.

A study on the efficient method of constrained iterative regular expression pattern matching (제약 반복적인 정규표현식 패턴 매칭의 효율적인 방법에 관한 연구)

  • Seo, Byung-Suk
    • Design & Manufacturing
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    • v.16 no.3
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    • pp.34-38
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    • 2022
  • Regular expression pattern matching is widely used in applications such as computer virus vaccine, NIDS and DNA sequencing analysis. Hardware-based pattern matching is used when high-performance processing is required due to time constraints. ReCPU, SMPU, and REMP, which are processor-based regular expression matching processors, have been proposed to solve the problem of the hardware-based method that requires resynthesis whenever a pattern is updated. However, these processor-based regular expression matching processors inefficiently handle repetitive operations of regular expressions. In this paper, we propose a new instruction set to improve the inefficient repetitive operations of ReCPU and SMPU. We propose REMPi, a regular expression matching processor that enables efficient iterative operations based on the REMP instruction set. REMPi improves the inefficient method of processing a particularly short sub-pattern as a repeat operation OR, and enables processing with a single instruction. In addition, by using a down counter and a counter stack, nested iterative operations are also efficiently processed. REMPi was described with Verilog and synthesized on Intel Stratix IV FPGA.

The Extended Operations for Generalized Quadratic Fuzzy Sets

  • Yun, Yong-Sik;Park, Jin-Won
    • Journal of the Korean Institute of Intelligent Systems
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    • v.20 no.4
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    • pp.592-595
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    • 2010
  • The extended algebraic operations are defined by applying the extension principle to normal algebraic operations. And these operations are calculated for some kinds of fuzzy numbers. In this paper, we get exact membership function as a results of calculation of these operations for generalized quadratic fuzzy sets.

Combining Regression Model and Time Series Model to a Set of Autocorrelated Data

  • Jee, Man-Won
    • Journal of the military operations research society of Korea
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    • v.8 no.1
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    • pp.71-76
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    • 1982
  • A procedure is established for combining a regression model and a time series model to fit to a set of autocorrelated data. This procedure is based on an iterative method to compute regression parameter estimates and time series parameter estimates simultaneously. The time series model which is discussed is basically AR(p) model, since MA(q) model or ARMA(p,q) model can be inverted to AR({$\infty$) model which can be approximated by AR(p) model. The procedure discussed in this articled is applied in general to any combination of regression model and time series model.

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