• 한국융합학회논문지
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• 제8권10호
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• pp.19-28
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• 2017

최근 컨테이너 항만에서는 점점 컨테이너선의 대형화에 따라 증가하는 물동량을 처리하기 위해, 하역장비들의 효율적인 배차 계획과 대기시간 최소화를 통해 작업 생산성을 높이는 다양한 방법들을 적용하고 있다. 본 연구에서는 생산성을 높이는 방법으로 기존 휴리스틱 방법론을 개선한 최적화 모형인 솔버(Solvers)를 적용하였다. 실험 계획은 6개의 샘플 문제를 통해 두 가지 목적함수인 공차주행시간 최소화와 지연시간 최소화의 수행 결과를 기존의 휴리스틱 방법론의 결과와 비교하는 것이다. 실험 결과 두 가지 목적함수 모두 6개의 샘플 문제 중에서 4개의 샘플 문제에서 최적화 모형이 휴리스틱 방법론보다 평균 5.3% 향상된 결과를 도출하였다.

• 한국컴퓨터정보학회논문지
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• 제15권9호
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• pp.1-8
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• 2010

하드웨어-소프트웨어 통합설계에서 다양한 설계제약 조건을 만족하는 임베디드 시스템 개발을 효율적으로 완료하기 위하여 하드웨어와 소프트웨어의 최적분할을 빠른 시간 안에 탐색하는 핵심기술이 필요하다. 본 논문에서는 다양한 하드웨어-소프트웨어 분할에 따른 매핑 조합 중 최적분할에 해당할 수 없는 조합들은 미리 선별하여 탐색대상에서 제외하는 것을 가능하게 하는 맞춤형 매핑 휴리스틱, CHARMS을 제시한다. CHARMS은 응용프로그램의 여러 태스크를 하드웨어 또는 소프트웨어로 매핑하면서, 단위시간 안에 처리되는 태스크의 수인 Parallelism과 일의 양인 Workload 로 Throughput을 예측하고 최적의 분할대상을 선별하는 기존의 휴리스틱보다 향상된 방법으로, 태스크들의 계산 복잡도를 고려하였으며, 설계제약 조건의 중요도를 다양하게 표현할 수 있는 weighted combo-metric을 활용한다. H.263 인코더 설계에서 CHARMS을 이용할 경우 매핑조합의 95.17%를 탐색 대상에서 제외할 수 있었음을 실험을 통하여 보였다.

• 한국산업정보학회논문지
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• 제27권1호
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• pp.37-48
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• 2022

본 연구에서는 공학설계 최적화 문제 해결을 위한 혼합 메타휴리스틱(Hybrid Meta-heuristic) 접근법을 제안된다. 공학 설계 최적화 문제는 다양한 형태의 변수를 가지며, 복잡한 제약조건들하에서 그 최적해를 구하는 문제로 이미 많은 기존 연구들을 통해 다양한 접근법들이 개발되어져 왔다. 하지만 그 효율성은 아직까지 크게 개선되지 못하고 있는 실정이다. 따라서 본 연구에서는 이러한 효율성을 개선하기 위한 새로운 접근법을 제안한다. 제안된 혼합 메타휴리스틱 접근법은 탐색 공간에 대한 전역적 탐색을 위해 유전알고리즘(Genetic Algorithm: GA) 접근법, 지역적 탐색을 위해 변동이웃탐색(Variable Neighborhood Search: VNS) 접근법과 언덕오르기(Hill Climbing: HC) 접근법을 혼합(GA-VNS-HC)하였다. 사례 연구에서는 다양한 형태의 공학설계 최적화 문제를 이용하여 본 연구에서 제안한 GA-VNS-HC 접근법의 우수성을 입증하였다.

• 대한안전경영과학회지
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• 제23권3호
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• pp.1-9
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• 2021

Crane is an important equipment for the transport of heavy goods in industrial sites, but it is also known as one of the most fatal machines. In order to reduce crane accidents, it is necessary to minimize human errors during crane operations. To achieve this, ergonomic design principles are recommended to be reflected from the crane design stage. The study analyzed the safety certification standards for crane that should be fulfilled at the crane design and manufacturing stage. This study selected five representative ergonomic design principles (feedback, compatibility, consistency, full-proof, and fail-safe) by surveying heuristic evaluation principles that are widely used for usability evaluation in early design stage. Next, the principles were applied to the safety certification standards to identify insufficient clauses. This study identified 12 insufficient clauses out of 119 in the current safety certification standards for crane and discussed their improvement directions to comply the ergonomic principles. The analysis results of this study can help of improving the safety certification standards and the method used in this study can also be applied to identify insufficient clauses in the safety certification standards for other industrial machines such as press machine and lift.

• 한국경영과학회지
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• 제22권4호
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• pp.17-35
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• 1997

This paper considers the efficient design of routing path and wavelength assignment in the single-hop WDM optical transport networks. The connection demands between node-pairs are given and a connection between a pair of nodes must be made by only one lightpath. It is assumed that no wavelength conversion is allowed and the physical topology of the network and the number of available wavelengths of a physical link are also given. This paper proposes the method to route a path and assign a wavelength to the path, which guarantees fairness to every node pair. In order to guarantee fairness and maximize connections, an optimization model is established, which successively maximizes minimum connection ratio to the demand of each node pair. A heuristic algorithm with polynomial iterations is developed for the problem since the problem is NP-hard. The heuristic algorithm is implemented and applied to the networks with real problem sizes. The results of the application are compared with GAMS/OSL.

• 산업경영시스템학회지
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• 제35권1호
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• pp.140-147
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• 2012

Vehicle routing problem is one of the traveling salesman problems with various conditions such as vehicle capacity limits, delivery time windows, as well as time dependent speeds in metropolitan area. In this research hourly vehicle moving speeds information in a typical metropolitan area are analyzed to use the results in the design procedure of VRP heuristic. Quality initial vehicle routing solutions can be obtained with adaption of the analysed results of the time periods with no vehicle speed changes. This strategy makes complicated time dependent vehicle speed simple to solve. Time dependent vehicle speeds are too important to ignore to obtain optimum vehicle routing search for real life logistics systems.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1044-1047
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• 1996

In this paper, GMDH(Group Method of Data Handling) algorithm, which is based on heuristic self organization to predict and identify the complex system, is applied to the control system of DC servo motor. The mathematical relation between input voltage and motor speed is obtained by GMDH algorithm. A design method of model following control system based on GMDH algorithm is developed. As a result of applying this method to DC servo motor, the simulation and experiment have shown that the developed method gives a good performance in tracking the reference model and in rejection of disturbance, in spite of constant load and changing load.

• Steel and Composite Structures
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• 제16권6호
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• pp.681-701
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• 2014

The main aim of this study is to propose an efficient meta-heuristic algorithm for topology optimization of geometrically nonlinear single layer domes by serially integration of computational advantages of firefly algorithm (FA) and particle swarm optimization (PSO). During the optimization process, the optimum number of rings, the optimum height of crown and tubular section of the member groups are determined considering geometric nonlinear behaviour of the domes. In the proposed algorithm, termed as FA-PSO, in the first stage an optimization process is accomplished using FA to explore the design space then, in the second stage, a local search is performed using PSO around the best solution found by FA. The optimum designs obtained by the proposed algorithm are compared with those reported in the literature and it is demonstrated that the FA-PSO converges to better solutions spending less computational cost emphasizing on the efficiency of the proposed algorithm.

• 한국경영과학회지
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• 제19권1호
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• pp.69-83
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• 1994

This paper deals with a capacitated ring-star network design problem (CRSNDP) with node capacity constraints. The CRSNDP is formulated as a mixed 0-1 integer problem, and a 2-phase heuristic solution procedure, ADD & VAM and RING, is developed, in which the CRSNDP is decomposed into two subproblems : the capacitated facility location problem (CFLP) and the traveling sales man problem (TSP). To solve the CFLP in phase I the ADD & VAM procedure selects hub nodes and their appropriate capacity from a candidate set and then assigns them user nodes under node capacity constraints. In phase II the RING procedure solves the TSP to interconnect the selected hubs to form a ring. Finally a solution of the CRSNDP can be achieved through combining two solution of phase I & II, thus a final design of the capacitated ring-star network is determined. The analysis of computational results on various random problems has shown that the 2-phase heuristic procedure produces a solution very fast even with large-scale problems.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 춘계학술대회
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• pp.210-212
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• 2017

플랫폼의 다양화에 따라 사용자의 학습경험을 최적화할 수 있는 디자인이 필요하다. 특히 모바일러닝의 확장은 플랫폼의 특성이 반영된 학습설계 전략을 요구하고 있으며, 이를 위하여 휴리스틱 평가를 이용하여 사용성 평가를 진행하였다. 이에 정보표시와 직관성, 간결성 등 시스템적인 요소가 사용자태도에 유의미한 수준의 영향을 미치는 것을 알 수 있었다.