• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1208-1211
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• 1996

In this paper, an efficient and robust robot path planning technique is discussed. Concentric Ripple Edge Evaluation and Progression( CREEP ) algorithm[1] has been elaborated and expanded to carry out 3-D path planning. Like the 2-D case, robot can always find a path, if one exists, in a densely cluttered, unknown and unstructured 3-D obstacle environment. 3-D space in which the robot is expected to navigate is modeled by stacking cubic cells. The generated path is resolution optimal once the terrain is fully explored by the robot or all the information about the terrain is given. Path planning times are significantly reduced by local path update. Accuracy and efficiency of wave propagation in CREEP algorithm are achieved by virtual concentric sphere wave propagation. Simulations in 2-D and 3-D spaces are performed and excellent results are demonstrated.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.1
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• pp.92-98
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• 2014

This paper proposes a hermite spline based D* algorithm for effective path planning of mobile robot to improve the detecting speed. In conventional path planning research, a robot is supposed to pass through predetermined centers of grid partitions of area. However it doesn't guarantee the optimal path during its navigation. In addition, a robot is hard to avoid obstacles effectively. The proposed algorithm in this paper makes use of stochastic characteristics of nonholonomic mobile robot and estimation of shortest path to curvature movement of the robot. The performance evaluation of the improved spline D* algorithm performed through simulation shows its effectiveness. Moreover, the experiment verifies that a robot can find the shortest path by building the curve paths while it is moving on the path in spline.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.1
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• pp.202-210
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• 2019

The obstacles modeling is a fundamental and significant issue for path planning and automatic navigation of Unmanned Surface Vehicle (USV). In this study, we propose a novel obstacles modeling method based on high resolution satellite images. It involves two main steps: extraction of obstacle features and construction of convex hulls. To extract the obstacle features, a series of operations such as sea-land segmentation, obstacles details enhancement, and morphological transformations are applied. Furthermore, an efficient algorithm is proposed to mask the obstacles into convex hulls, which mainly includes the cluster analysis of obstacles area and the determination rules of edge points. Experimental results demonstrate that the models achieved by the proposed method and the manual have high similarity. As an application, the model is used to find the optimal path for USV. The study shows that the obstacles modeling method is feasible, and it can be applied to USV path planning.

• Journal of Aerospace System Engineering
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• v.14 no.6
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• pp.1-9
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• 2020

Global e-commerce and delivery companies are actively pursuing last-mile delivery service using drones, and various delivery schedule planning studies have been conducted. In this study, separate individual route networks were constructed to reflect drone route constraints such as prohibited airspace and truck route constraints such as rivers, which previous studies did not incorporate. The A* algorithm was used to calculate the shortest path distance matrix between the starting point and destinations. In addition, we proposed an optimal delivery schedule plan using genetic algorithms and applied it to compare the efficiency with that of vehicle-only delivery.

• Health Policy and Management
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• v.1 no.1
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• pp.136-152
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• 1991

The study was conducted to project supply and demand of the physicians from year 1991 to year 2010 based on the analysis of supply and demand of the physicians up to year 1989. Results of the study will provide information for the physicians manpower planning of the 7th 5-year Economic Social Development Planning(1992-1996) and contribute to the overall health manpower planning for the 21the century. It is projected that physician will be oversupplied from the very near future based on the current productivity or underestimated based on the optimal productivity. Thus, it is desirable not to change size of training and education during the 7the 5-year planning period and re-examine the status of the physician manpower at the end of the 7th 5-year period taking into consideration medical services utilization pattern, patients' satisfaction, and physicians' productivity.

• Journal of the Korean Institute of Educational Facilities
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• v.14 no.2
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• pp.101-104
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• 2007

• Proceedings of the KOR-KST Conference
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• 2007.11a
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• pp.229-238
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• 2007

• Proceedings of the KIEE Conference
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• 1985.07a
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• pp.111-114
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• 1985

• Proceedings of the KIEE Conference
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• 1983.07a
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• pp.167-169
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• 1983

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.617-620
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• 1987