• 제어로봇시스템학회논문지
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• 제8권12호
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• pp.1048-1055
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• 2002

The problem of generating torch paths for 2D laser cutting of a stock plate nested with a set of free-formed parts is investigated. The objective is to minimize the total length of the torch path starting from a blown depot, then visiting all the given Parts, and retuning back to the depot. A torch Path consists of the depot and Piercing Points each of which is to be specified for cutting a part. The torch path optimization problem is shown to be formulated as an extended version of the standard travelling salesman problem To solve the problem, a hybrid genetic algorithm is proposed. In order to improve the speed of evolution convergence, the algorithm employs a genetic algorithm for global search and a combination of an optimization technique and a genetic algorithm for local optimization. Traditional genetic operators developed for continuous optimization problems are used to effectively deal with the continuous nature of piercing point positions. Computational results are provided to illustrate the validity of the proposed algorithm.

• 한국경영과학회지
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• 제25권3호
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• pp.81-89
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• 2000

The real-time multicast problem is to construct a multicast tree starting from a source node and including multiple destination nodes and that has minimum network cost with delay constraints. It is known that to find a tree of the minimum network cost is the Steiner Tree problem which is NP-complete. In this paper, we propose a genetic algorithm to solve the multicast tree with minimum network cost and the delay constraints. The computational results obtained by comparing an existing algorithm. Kompella algorithm, and the proposed algorithm show that our algorithm tends to find lower network cost on the average than Kompella algorithm does.

• 로봇학회논문지
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• 제5권1호
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• pp.41-47
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• 2010

This paper proposes a path planning method of a mobile robot in two-dimensional work space. The path planning method is based on a cell decomposition approach. To create a path which consists of a number of line segments, the Delaunay Triangulation algorithm is used. Using the cells produced by the Delaunay Triangulation algorithm, a mesh generation algorithm connects the starting position to the goal position. Dijkstra algorithm is used to find the shortest distance path. Greedy algorithm optimizes the path by deleting the path segments which detours without collision with obstacles.

• 정보처리학회논문지B
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• 제11B권3호
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• pp.247-256
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• 2004

본 논문에서는 영상의 시공간적인 특성과 움직임 벡터의 중심 지향적 분포 특성을 이용하는 예측 탐색 알고리즘을 제안한다. 제안된 알고리즘을 이린 프레임 블록으로부터 예측된 움직임 벡터, 분할된 탐색 구간에 속하는 후보 벡터와 현재 프레임 블록의 이웃 블록으로 예측된 움직임 벡터 중에서 가장 작은 SAD 값을 갖는 점을 정확한 움직임 벡터를 찾기 위한 초기 탐색점 위치로 결정한다. 그리고 초기 탐색점 위치로 이동하여 움직임 크기에 따라 적응적인 탐색 패턴으로 탐색을 수행판다. 실험 결과 제안된 방식은 FS를 제외한 기존의 대표적인 고속 탐색 방식들에 비해 PSNR 값에 있어서 평균적으로 0.05∼0.34dB 개선되고 영상에 따라 최고 0.75dB 정도 우수한 결과를 나타내었다.

• 한국시뮬레이션학회논문지
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• 제19권4호
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• pp.129-137
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• 2010

지금까지 연구된 최소비용 경로 알고리즘들은 정점과 정점간의 가중치가 부여된 간선을 갖는 그래프를 이용한다. 그러나, 바다와 같은 넓은 공간에서 시점과 종점사이에 섬과 같은 임의의 형태의 장애물이 존재하고 시점으로부터 종점까지의 최단거리를 찾고자 할 때, 이 알고리즘들은 최소비용 경로를 구하기 위해 장애물이 없는 공간상의 위치를 모두 정점으로 하고 인접정점들 사이에 가중치를 부여한 간선이 준비되어야 하므로 그 수가 매우 방대해져 공간복잡도가 높아지고 실행시간이 오래 걸리게 된다. 이에 본 논문에서는 정점과 가중치 간선의 그래프 자료구조를 이용하지 않고 장애물의 경계위치와 시점 및 종점위치 정보만을 이용하여 장애물을 우회하는 최소비용 경로를 탐색하는 효율적 알고리즘을 제안하고자 한다. 장애물을 포함하는 최소 경계 사각형의 행과 열의 크기(위치의 수)를 각각 m과 n이라 할 때, 제안한 알고리즘은 최대 O(mn)의 시간 복잡도를 가진다. 이 성능은 제안한 알고리즘이 기존 알고리즘에 비해 효율적임을 보여준다.

• 한국정밀공학회지
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• 제29권4호
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• pp.469-478
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• 2012

This study aims to discover the optimal pipe layout for a ship, which generally needs a lot of time, efforts and experiences. Genetic algorithm was utilized to search for the optimum. Here the optimum stands for the minimum pipe length between two given points. Genetic algorithm is applied to planar pipe layout problems to confirm plausible and efficiency. Sub-programs are written to find optimal layout for the problems. Obstacles are laid in between the starting point and the terminal point. Pipe is supposed to bypass those obstacles. Optimal layout between the specified two points can be found using the genetic algorithm. Each route was searched for three case models in two-dimensional plane. In consequence of this, it discovered the optimum route with the minimized distance in three case models. Through this study, it is possible to apply optimization of ship pipe route to an actual ship using genetic algorithm.

• ETRI Journal
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• 제22권3호
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• pp.1-9
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• 2000

Self-Clocked Fair Queueing (SCFQ) algorithm has been considered as an attractive packet scheduling algorithm because of its implementation simplicity, but it has unbounded delay property in some input traffic conditions. In this paper, we propose a Rate Proportional SCFQ (RP-SCFQ) algorithm which is a rate proportional version of SCFQ. If any fair queueing algorithm can be categorized into the rate proportional class and input is constrained by a leaky bucket, its delay is bounded and the same as that of Weighted Fair Queueing (WFQ) which is known as an optimal fair queueing algorithm. RP-SCFQ calculates the timestamps of packets arriving during the transmission of a packet using the current value of system potential updated at every packet departing instant and uses a starting potential when it updates the system potential. By doing so, RP-SCFQ can have the rate proportional property. RP-SCFQ is appropriate for high-speed packet-switched networks since its implementation complexity is low while it guarantees the bounded delay even in the worst-case input traffic conditions.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.413-418
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• 1996

Alternate pirn winding is more difficult to control than others because starting points of its traverse strokes are changed alternately through the winding operations. However, the alternate pirn winding is ye useful method because the yarn can be hardly broken when it is unwinded from full packaged bobbin. This paper presents kinematic control algorithm for the alternate pirn. The proposed algorithm can decide the values of control variables such as bobbin speed and traverse speed from the given input parameters and constraints by using the kinematic relations of the winding mechanism. The compute simulations and experimental verifications of the developed winding control algorithm are carried out It is concluded that the proposed algorithm is an efficient and reliable alternative to traditional trial and error control methods.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.827-828
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• 2006

This paper presents a vehicle control algorithm for Personal Rapid Transit (PRT) system. PRT system is a one-way direction network system which is composed of guideway branches, merging/diverging points. Vehicle control algorithm can be divided into two kinds. Those are merging control algorithm and the other. We emphasized on the merging control algorithm. For that, we first devised a front/virtual front vehicle finding strategies. Properly determined front/virtual front vehicle is the starting point of vehicle control. The objects of merging control are to avoid collision and to pass the merging point fluently. Which implies that jerk constraint and limits of acceleration and deceleration etc. are should be considered. To verify the validation of the vehicle algorithm, we executed simulations and presented test results.

• 전자공학회논문지B
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• 제28B권7호
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• pp.578-589
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• 1991

In this paper, there is proposed a novel concept of Incremintal Circle Transform which can describe the boundary contour of a two-dimensional object without object without occlusions. And a pattern recognition algorithm to determine the posture of an object is developed with the aid of line integral and similarity transform. Also, It is confirmed via experiments that the algorithm can find the posture of an object in a very fast manner independent of the starting point for boundary coding and the position of the object.