• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.904-907
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• 1996

In this paper, we propose an efficient collision-free path planning method of two cooperating robot manipulators grasping a common object rigidly. For given two robots and an object, the procedure is described which constructs the reduced dimensional configuration space by the kinematic analysis of two cooperating robot manipulators. A path planning algorithm without explicit representation of configuration obstacles is also described. The primary steps of the algorithm is as follows. First, we compute a graph which represents the skeleton of the free configuration space. Second, a connection between an initial and a goal configuration to the graph is searched to find a collision-free path.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.5
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• pp.413-418
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• 2012

This paper presents a multi-robot path planner for environment exploration and monitoring. Robotics systems are being widely used as data measurement tools, especially in dangerous environment. For large scale environment monitoring, multiple robots are required in order to save time. The path planner should not only consider the collision avoidance but efficient coordination of robots for optimal measurements. Nonlinear spring force based planning algorithm is integrated with the spatial gradient following path planner. Perturbation/Correlation based estimation of spatial gradient is applied. An algorithm of tuning the stiffness for robot coordination is presented. The performance of the proposed algorithm is discussed with simulation results.

• Journal of Mechanical Science and Technology
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• v.17 no.12
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• pp.1876-1885
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• 2003

The artificial potential field (APF) methods provide simple and efficient motion planners for practical purposes. However, these methods have a local minimum problem, which can trap an object before reaching its goal. The local minimum problem is sometimes inevitable when an object moves in unknown environments, because the object cannot predict local minima before it detects obstacles forming the local minima. The avoidance of local minima has been an active research topic in the potential field based path planing. In this study, we propose a new concept using a virtual obstacle to escape local minima that occur in local path planning. A virtual obstacle is located around local minima to repel an object from local minima. We also propose the discrete modeling method for the modeling of arbitrary shaped objects used in this approach. This modeling method is adaptable for real-time path planning because it is reliable and provides lower complexity.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.154-157
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• 2003

This paper presents an efficient real-time tool-path planning method for interpolation of NURBS surfaces in CNC machining. The proposed tool-path planning method is based on an improved iso-scallop strategy and can provide better precision than the existing methods. The proposed method is designed such that tool-path planning is easily managed in realtime. It proposed a new algorithm, for regulation of a scallop height, which can efficiently generate tool-paths and can save machining time compared with the existing method. Through computer simulations, the performance of the proposed method is analyzed and compared with the existing method in terms of feedrate. total machining time and a degree of constraint on the scallop height.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12A
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• pp.1917-1921
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• 1999

In this paper, we studied the method of path distribution in order to increase reliability of the network by reducing path congestion, solving the problems of increasing blocking statistics, and increasing the utilization of network resource. A scheme of efficient path calculation which can reduce the traffic congestion in an arbitrary link is proposed by path calculation equations considering link occupation rates. A rapid method of establishing a connection which can efficiently cope with accidental connection failure are studied.

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.4
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• pp.31-37
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• 2011

Recently, MANET(Mobile Ad-hoc Network) is developing increasingly in the wireless network. MANET has weakness because phases change frequently and MANET doesn't have middle management system. Every node which consists of MANET has to perform data forwarding, but traceback is not reliable if these nodes do malicious action owing to attack. It also is not easy to find location of attacker when it is attacked as moving of nodes. In this paper, we propose a hierarchical-based traceback method that reduce waste of memory and can manage path information efficiently. In order to manage trace path information and reduce using resource in the cluster head after network is formed to cluster, method which recomposes the path efficiently is proposed. Proposed method in this paper can reduce path trace failure rate remarkably due to moving of nodes. It can also reduce the cost for traceback and time it takes to collect information.

• Journal of Information Processing Systems
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• v.13 no.1
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• pp.104-113
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• 2017

In this paper, we present an approach to transmit data from the source to the destination through a minimal path (least-cost path) in a computer network of n nodes. The motivation behind our approach is to address the problem of finding a minimal path between the source and destination. From the work we have studied, we found that a Steiner tree with bounded Steiner vertices offers a good solution. A novel algorithm to construct a Steiner tree with vertices and bounded Steiner vertices is proposed in this paper. The algorithm finds a path from each source to each destination at a minimum cost and minimum number of Steiner vertices. We propose both the sequential and parallel versions. We also conducted a comparative study of sequential and parallel versions based on time complexity, which proved that parallel implementation is more efficient than sequential.

• 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.

• The Journal of Korea Robotics Society
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• v.18 no.3
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• pp.316-322
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• 2023

The increasing popularity of autonomous unmanned aerial vehicles (UAVs) can be attributed to their wide range of applications. 3D path planning is one of the crucial components enabling autonomous flight. In this paper, we present a novel 3D path planning algorithm that generates and utilizes curvature-based trajectories. Our approach leverages circular properties, offering notable advantages. First, circular trajectories make collision detection easier. Second, the planning procedure is streamlined by eliminating the need for the spline process to generate dynamically feasible trajectories. To validate our proposed algorithm, we conducted simulations in Gazebo Simulator. Within the simulation, we placed various obstacles such as pillars, nets, trees, and walls. The results demonstrate the efficacy and potential of our proposed algorithm in facilitating efficient and reliable 3D path planning for UAVs.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.144-145
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• 2022

Since the marking robot draws lines by point-to-point operation, the robot's shifting path greatly affects the working time and productivity. Therefore, it is required to analyze the movement method based on the robot's motion and plan to minimize the movement time. Therefore, this study proposes a method that can optimize the robot's shifting path to minimize the working time of the marking robot. Through the results of this study, it is expected that the non-working time of the marking robot will be reduced and the efficient operation will be possible.