• Title/Summary/Keyword: heuristic rules

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Auto-Tuning PID Controller using Some Heuristic Rules (경험적 규칙을 이용한 자동 동조 PID제어기)

  • 이창구;김성중;황형수
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.39 no.5
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    • pp.485-493
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    • 1990
  • The idea of expert control is to incorporate a rule based expert system in a feedback control system. In this paper, we present some heuristic rules based on relay experiment for the choice of controller structure and the setting of the controller parameters. Heuristic rules are used as an element of the feedback loop in an auto-tuning PID controller. The algorithms are coded in a form which is as pure as possible and the heuristic logic is implemented with the rules. This paper reports an implementation of an expert controller on microcomputer-based system, including an industrial programmable controller.

Development of heuristic method for job shop scheduling with alternative machines (대안기계를 갖는 Jop Shop scheduling을 위한 발견적기법의 개발)

  • 최동순;정병희
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1996.10a
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    • pp.303-306
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    • 1996
  • This paper proposes a heuristic method for job shop scheduling with alternative machines. Our heuristic suggests four machine-selecting rules and two priority dispatching rules for modifying existent ones considering alternative machines, and then it extends existing nondelay/active job shop schedule generation. This heuristic provides good criteria(rules) in the selection of a proper machine among those performing a specific operation and for the dispatch of an operation to a selected machine and thus these rules permit the efficient job shop scheduling with alternative machines. The performances of our four machine-selecting rules in addition to the two priority dispatching rules, applied together with the existing 17 rules, are experimented and evaluated, respectively.

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A Heuristic Method for Job Shop Scheduling Considering Alternative Machines (대안기계를 고려한 Job Shop Scheduling의 발견적 기법)

  • 최동순;정병희
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.20 no.43
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    • pp.127-137
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    • 1997
  • This paper proposes a heuristic method for job shop scheduling with alternative machines. Our heuristic suggests two machine-selecting rules and two priority dispatching rules for modifying existent ones considering alternative machines, and then it extends existing nondelay/active job shop schedule generation. This heuristic provides good criteria(rules) in the selection of a proper machine among those performing a specific operation and for the dispatch of an operation to a selected machine and thus these rules permit the efficient job shop scheduling with alternative machines. The performances of our two machine-selecting rules in addition to the two priority dispatching rules, applied together with the existing 17 rules, are experimented and evaluated, respectively.

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Heuristic Search in Coordination of Overcurrent Protection of Power Distribution Systems (배전선로 보호기기 정정에서의 경험적 탐색 방법)

  • Lee, Seung-Jae;Park, Young-Moon;Lee, Jeong-Won
    • Proceedings of the KIEE Conference
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    • 1990.11a
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    • pp.191-196
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    • 1990
  • By the nature of distribution system, the coordination process of protection devices depends on various heuristic rules. This paper reviews the practical rules that adopted in coordination, and proposes some heuristic rules improving the coordination process.

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Rule Based Auto-Tuning PID Controller with Feedforward Path (피드포워드 경로를 갖는 규칙 기반 자동동조 PID제어기)

  • 윤양웅;박왈서
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.41 no.4
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    • pp.355-361
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    • 1992
  • In this paper, some rules for auto- tuning of feedback-feedforward controller in variable load and disturbance are presented. The parameters of feedback PID controller are determined by heuristic rules based on input regulation experiment, and the parameters of feedforward controller are determined by result rules based on spectral factorization, minimum variance, and polynomial equation. These heuristic and result rules are used as an element of the feedback loop in an auto-tuning feedback-feedforward controller. The robust and accurate control performance is demonstrated by computer simulation.

DYNAMIC SELECTION OF DISPATCHING RULES BY ARTIFICIAL NEURAL NETWORKS

  • Lee, Jae-Sik
    • Management Science and Financial Engineering
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    • v.3 no.2
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    • pp.29-43
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    • 1997
  • Many heuristics have been developed in order to overcome the computational complexity of job shop problems. In this research, we develop a new heuristic by selecting four simple dispatching rules, i.e., SPT, LPT, SR and LR, dynamically as scheduling proceeds. The selection is accomplished by using artificial neural networks. As a result of testing on 50 problems, the makespan obtained by our heuristic is, on the average, 13.0% shorter than the longest makespan, and 0.4% shorter than the shortest makespan obtained by existing dispatching rules.

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A Study on the Design of Adaptive Controller with Supervision Function (감독기능을 갖는 적응제어기 구성에 관한 연구)

  • 이창구;권오형;황형수;김성중
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.37 no.12
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    • pp.894-902
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    • 1988
  • In this paper, a method for the design of robust adaptive controller using the heuristic rules of industrial engineers is presented. This scheme works on the basis of heuristic rules and includes a supervisor, a system identifier and a detuner. The supervisor detects onsetting instability based on the analysis of the amplitude and the trend of error signal, also selects running controllers. Upon detecting instability, the controller is switched to a PID algorithm and run recursively until stability is restored. Simultaneously, new input / output data is gathered and the system identifier runs to get critical sensitivity (kc) and critical period(tc). Based on the new values(kc, tc), a GPC controller is redesigned and normal GPC is finally run. The algorithm described in this paper belongs to the supervised adaptive control category with a limited use of heuristic rules. Finally, we show the robust of this scheme by simulated example.

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Heuristics for Job Shop Scheduling Problems with Progressive Weighted Tardiness Penalties and Inter-machine Overlapping Sequence-dependent Setup Times

  • Mongkalig, Chatpon;Tabucanon, Mario T.;Hop, Nguyen Van
    • Industrial Engineering and Management Systems
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    • v.4 no.1
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    • pp.1-22
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    • 2005
  • This paper presents new scheduling heuristics, namely Mean Progressive Weighted Tardiness Estimator (MPWT) Heuristic Method and modified priority rules with sequence-dependent setup times consideration. These are designed to solve job shop scheduling problems with new performance measures - progressive weighted tardiness penalties. More realistic constraints, which are inter-machine overlapping sequence-dependent setup times, are considered. In real production environments, inter-machine overlapping sequence-dependent setups are significant. Therefore, modified scheduling generation algorithms of active and nondelay schedules for job shop problems with inter-machine overlapping sequence-dependent setup times are proposed in this paper. In addition, new customer-based measures of performance, which are total earliness and progressive weighted tardiness, and total progressive weighted tardiness, are proposed. The objective of the first experiment is to compare the proposed priority rules with the consideration of sequence-dependent setup times and the standard priority rules without setup times consideration. The results indicate that the proposed priority rules with setup times consideration are superior to the standard priority rules without the consideration of setup times. From the second experiment and the third experiment to compare the proposed MPWT heuristic approach with the efficient priority rules with setup times consideration, the MPWT heuristic method is significantly superior to the Batched Apparent Tardiness Cost with Sequence-dependent Setups (BATCS) rule, and other priority rules based on total earliness and progressive weighted tardiness, and total earliness and tardiness.

Frequency Reassignment Problem in Code Division Multiple Access Networks

  • Han Jung-Hee
    • Management Science and Financial Engineering
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    • v.12 no.1
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    • pp.127-142
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    • 2006
  • In this paper, we present a frequency reassignment problem (FRP) that arises when we add new base stations to resolve hot-spots or to expand the coverage of a code division multiple access (CDMA) network. For this problem, we develop an integer programming (IP) model along with some valid inequalities and preprocessing rules. Also, we develop an effective heuristic procedure that solves two sub-problems induced from the original problem in repetition. Computational results show that the proposed heuristic procedure finds a feasible solution of good quality within reasonable computation time. Also, the lower bound by-produced from the heuristic procedure is quite strong.

A heuristic technique for jop shop scheduling using operation due dates (공정납기를 이용한 jop shop 일정계획의 발견적 기법)

  • 배상윤;김여근;김영균
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1996.04a
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    • pp.46-49
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    • 1996
  • This paper presents a multi-pass heuristic for job shop scheduling with due dates. The proposed heuristic iteratively improves solutions based on operation due dates. To find a good solution efficiently, a method for searching the neighborhood of current schedule is developed. The heuristic is compared with two existing heuristics as well as several dispatching rules in terms of solution quality and computation time. The experimental results show that the proposed approach is promising.

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