• 대한안전경영과학회지
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• 제14권1호
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• pp.167-177
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• 2012

In this paper, we raised the performance of heuristic algorithm to assign job to workers in parallel line inspection process without sequence. In previous research, we developed the heuristic algorithm. But the heuristic algorithm can't find optimal solution perfectly. In order to solve this problem, we proposed new method to make initial solution called FN(First Next) method and combined the new FN method and old FE method using previous heuristic algorithm. Experiments of assigning job are performed to evaluate performance of this FE+FN heuristic algorithm. The result shows that the FE+FN heuristic algorithm can find the optimal solution to assign job to workers evenly in many type of cases. Especially, in case there are optimal solutions, this heuristic algorithm can find the optimal solution perfectly.

• 대한산업공학회지
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• 제14권2호
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• pp.41-51
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• 1988

In this paper an efficient heuristic for the generalized assignment problem(GAP) is presented. A new lower bound that is slightly improved by adding the feasibility constraint is used to measure the quality of solutions obtained by the heuristic. The heuristic was tested on a number of large-scale random problems and a large sample of small problems. The heuristic appears to be better than the best previously existing heuristic for GAP. Its effectiveness in comparison of running times and closenesses to lower bound is discussed.

• 한국정보처리학회논문지
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• 제4권10호
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• pp.2477-2484
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• 1997

$A^{\ast}$와 같은 Best-first 휴리스틱 탐색 알고리즘들은 인공지능 분야에서 많은 문제를 해결하는데 가장 중요한 기법들 중의 하나이다. 휴리스틱 탐색의 공통적 특성은 계산의 복잡도가 매우 높다는 것이며, 이는 수많은 노드를 가진 지도에서 경로를 찾는 것과 같은 실질적인 문제 영역에 적용되기 어렵다는 것을 나타낸다. 본 논문에서는, 몇몇 휴리스틱 탐색 알고리즘이 언급되고, path-sensitive heuristic이라 불리는 새로운 동적 가중치 휴리스틱 방법이 제안되었다. 이 방법은 동적 가중치 휴리스틱에 기초하였고, 동적 휴리스틱은 admissible heuristic을 허용하지 않거나 휴리스틱의 정확도가 떨어지는 실제 문제 영역에서 탐색 노력을 줄이는데 사용될 수 있다. 탐색 과정 동안 ${\omega}$(가중치)가 동적으로 조정된다는 점에서, 다른 동적 가중치 휴리스틱 알고리즘과 구분된다.

• 경영과학
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• 제12권2호
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• pp.77-87
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• 1995

In this paper we develop an efficient heuristic algorithm for the problem of scheduling n sequence-dependent jobs on a basic processor to minimize makespan. Efficient solution methods are already known for the sequence- independent case. But for the sequence-dependent case, this problem belongs to a set of strong NP-complete problems. We present a heuristic which is similar to shortest setup time heuristic but opportunity cost of setup time rather than shortest setup time is used for choosing next job. This heuristic algorithm has same computational complexity and worst case ratio as the shortest setup time heuristic. We used Wilcoxon signed rank test to show that our heuristic is superior to nearest setup time heuristic in term of average behavior.

• 대한안전경영과학회지
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• 제10권3호
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• pp.253-265
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• 2008

In this paper, we developed a heuristic algorithm to assign job to workers in parallel line inspection process without sequence. Objective of assigning job in inspection process is only to assign job to workers evenly. But this objective needs much time and effort since there are many cases in assigning job and cases increase geometrically if the number of job and worker increases. In order to solve this problem, we proposed heuristic algorithm to assign job to workers evenly. Experiments of assigning job are performed to evaluate performance of this heuristic algorithm. The result shows that heuristic algorithm can find the optimal solution to assign job to workers evenly in many type of cases. Especially, in case there are more than two optimal solutions, this heuristic algorithm can find the optimal solution with 98% accuracy.

• 지능정보연구
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• 제1권1호
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• pp.61-72
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• 1995

Dynamic and explicit ordering of strategies is a key process in modeling knowledge-level problem-solving behavior. This paper addressed the important problem of howl to make the scheduler more knowledge-intensive in a way that facilitates the acquisition, integration, and maintenance of the scheduler control knowledge. The solution a, pp.oach described in this paper involved formulating the scheduler task as a heuristic classification problem, and then implementing it as a classification expert system. By doing this, the wide spectrum of known methods of acquiring, refining, and maintaining the knowledge of a classification expert system are a, pp.icable to the scheduler control knowledge. One important innovation of this research is that of recursive heuristic classification : this paper demonstrates that it is possible to formulate and solve a key subcomponent of heuristic classification as heuristic classification problem. Another key innovation is the creation of a method of dynamic heuristic classification : the classification alternatives that are selected among are dynamically generated in real-time and then evidence is gathered for and aginst these alternatives. In contrast, the normal model of heuristic classification is that of structured selection between a set of preenumerated fixed alternatives.

• 한국공간정보시스템학회 논문지
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• 제10권2호
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• pp.35-48
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• 2008

이 논문에서는 단말기 기반 시스템에서 경로를 탐색할 때 탐색비용을 줄이고, 경로탐색의 질을 높이기 위해 동적 휴리스틱을 제안한다. 동적 휴리스틱이란 고정된 정보가 아닌 서버로부터 지속적으로 전송받는 휴리스틱으로, 교통정보를 계산한 데이터이다. 서버 기반의 경로탐색 서비스는 서버에서 경로를 탐색하여 결과를 클라이언트에 제공하지만, 제안하는 방법은 휴리스틱 정보만을 클라이언트에 전송하고 이를 활용하여 경로탐색을 하게 된다. 이 논문에서는 제안하는 동적 휴리스틱을 적용하기 위해 새로운 알고리즘을 제안한다. 제안하는 동적 휴리스틱은 지도를 그리드로 나누고, 각 그리드는 구역내 간선들의 최저속도 정보를 가진다. 그리드의 최저속도가 기준치에 미달되면 해당 그리드를 제거하고 경로를 탐색한다.

• 대한산업공학회지
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• 제33권1호
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• pp.86-98
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• 2007

This paper presents a heuristic algorithm for the traveling salesman problem with time windows (TSPTW). Aniterative insertion algorithm as a constructive search heuristic and a hybrid meta heuristic combining simulatedannealing and tabu search with the randomized selection of 2-interchange and a simple move operator as animproving search heuristic are proposed, Computational tests performed on 400 benchmark problem instancesshow that the proposed algorithm generates optimal or near-optimal solutions in most cases. New best knownheuristic values for many benchmark problem sets were obtained using the proposed approach.

• 산업공학
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• 제21권1호
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• pp.8-17
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• 2008

A new search procedure, VLT(Vertex Line Tracing) heuristic, for two dimensional irregular shapes nesting problem was suggested in this study. The VLT heuristic was suggested to the nesting problem to overcome disadvantages of the existing NFP(No-Fit-Polygon) method. This VLT heuristic was compared with the results of the existing benchmark problems suggested by Albano, Hopper, and Burke. The results of the VLT heuristic give efficient solutions in the point of the scrap ratio and computation time. A computer program, NestLogic, using C++ for VLT heuristic was also developed for this nesting problem.

• International Journal of Ocean System Engineering
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• 제3권1호
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• pp.22-32
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• 2013

A heuristic physical theory of diffraction (PTD) for an acoustic impedance wedge is proposed. This method is based on Ufimtsev's three-dimensional PTD, which is derived for an acoustic soft or hard wedge. We modify the original PTD according to the process of physical optics (or the Kirchhoff approximation) to obtain a 3D heuristic diffraction model for an impedance wedge. In principle, our result is equivalent to Luebbers' model presented in electromagnetism. Moreover, our approach provides a useful insight into the theoretical basis of the existing heuristic diffraction methods. The derived heuristic PTD is applied to an arbitrary impedance polygon, and a simple PTD formula is derived as a supplement to the physical optics formula.