• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.6 s.312
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• pp.1-8
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• 2006

Many researches on path planning and obstacle avoidance for the fundamentals of mobile robot have been done recently. Informations from various sensors can be used to find obstacles and plan feasible path. In spite of many solutions of finding optimal path, each can be applied in only a constrained condition. This means that it is difficult to find university good algorithm. An optimal path with a complicated computation generates a time delay which cannot avoid moving obstacles. In this paper, we propose an algorithm of path planning and obstacle avoidance for mobile robot. We call the proposed method Random Access Sequence(RAS) method. In the proposed method, a small region is set first and numbers are assigned to its neighbors, then the path is selected using these numbers and cumulative numbers. It has an advantage of fast planning time and completeness of path if one exists. This means that new path selection may be possible within short time and that helps a robot to avoid obstacle in dynamic environments. Using the information of the start and destination position, the RAS can be performed for collision-free navigation by reforming feasible paths repeatedly in dynamic environments.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.4
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• pp.1256-1275
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• 2014

As one of the new self-organizing and self-configuration broadband networks, wireless mesh networks are being increasingly attractive. In order to solve the load balancing problem in wireless mesh networks, this paper proposes a novel multi-path routing algorithm based on clustering (Cluster_MMesh) for wireless mesh networks. In the clustering stage, on the basis of the maximum connectivity clustering algorithm and k-hop clustering algorithm, according to the idea of maximum connectivity, a new concept of node connectivity degree is proposed in this paper, which can make the selection of cluster head more simple and reasonable. While clustering, the node which has less expected load in the candidate border gateway node set will be selected as the border gateway node. In the multi-path routing establishment stage, we use the intra-clustering multi-path routing algorithm and inter-clustering multi-path routing algorithm to establish multi-path routing from the source node to the destination node. At last, in the traffic allocation stage, we will use the virtual disjoint multi-path model (Vdmp) to allocate the network traffic. Simulation results show that the Cluster_MMesh routing algorithm can help increase the packet delivery rate, reduce the average end to end delay, and improve the network performance.

• Journal of applied mathematics & informatics
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• v.32 no.1_2
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• pp.255-266
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• 2014

For a connected graph G = (V,E) of order at least two, a set S of vertices of G is a monophonic set of G if each vertex v of G lies on an x - y monophonic path for some elements x and y in S. The minimum cardinality of a monophonic set of G is the monophonic number of G, denoted by m(G). Certain general properties satisfied by the monophonic sets are studied. Graphs G of order p with m(G) = 2 or p or p - 1 are characterized. For every pair a, b of positive integers with $2{\leq}a{\leq}b$, there is a connected graph G with m(G) = a and g(G) = b, where g(G) is the geodetic number of G. Also we study how the monophonic number of a graph is affected when pendant edges are added to the graph.

• Journal of Ocean Engineering and Technology
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• v.23 no.6
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• pp.146-155
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• 2009

This paper considers the path tracking problem in a horizontal plane for underactuated (or non-holonomic) autonomous underwater vehicles (AUVs). Underwater mapping has been an important mission for AUVs. Recently, underwater docking has also become a main research field of AUVs. These kinds of missions basically require accurate attitude and trajectory control performance. However, the non-holonomic problem should be solved to achieve accurate path tracking for the torpedo-type of AUVs. In this paper, resolved motion and acceleration control (RMAC) is considered as a path tracking controller for an underactuated torpedo-shaped AUV, ISiMi. A set of numerical simulations is carried out to illustrate the effectiveness of the proposed RMAC scheme, and experimental data with ISiMi100 and discussions are presented.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.12
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• pp.38-45
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• 2003

Recently, localized QoS routing scheme was recently proposed for overcome drawbacks of global state QoS routing schemes. Localized QoS routing dose not exchange QoS states among routers, but use virtual capacity based routing scheme instead. In localized QoS routing, to archive good performance, a set of candidate paths must be selected between the source and the destination effectively. In this paper we propose a few heuristics for effective path selection and develop path selection algorithms based on the heuristics. More detail analysis of the proposed algorithm is presented with simulation results which demonstrate that the path selection method can very affect the performance of localized QoS routing.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.10
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• pp.582-590
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• 2000

A fast optimal path planning algorithm using the analog Cellular Nonlinear Circuits(CNC) is proposed. The analog circuits based optimal path planning is very useful since most of the optimal path planning problems require real time computation. There has already been a previous study to implement the dynamic programming with analog circuits. However, it could not be applied for the practically large size of problems since the algorithm employs the mechanism of reducing its input current/voltage by the amount of cost, which causes outputs of distant cells to become zero. In this study, a subgoal-based dynamic programming algorithm to compute the optimal path is proposed. In the algorithm, the optimal paths are computed regardless of the distance between the starting and the goal points. It finds subgoals starting from the starting point when the output of the starting cell is raised from its initial value. The subgoal is set as the next initial position to find the next subgoal until the final goal is reached. The global optimality of the proposed algorithm is discussed and two different kinds of simulations have been done for the proposed algorithm.

• Journal of the Korea Society of Computer and Information
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• v.19 no.5
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• pp.89-98
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• 2014

This paper suggests heuristic algorithm for single-model simple assembly line balancing problem that is a kind of NP-hard problem. This problem primarily can be solved metaheuristic method. This heuristic algorithm set the main-path that has a most number of operations from start to end-product. Then the clustering algorithm can be assigns operations to each workstation within cycle time follow main-path. This algorithm decides minimum number of workstations and can be reduces the cycle time. This algorithm can be better performance then metaheuristic methods.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.1
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• pp.40-51
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• 2009

A paired many-to-many k-disjoint path cover (paired k-DPC) of a graph G is a set of k disjoint paths joining k distinct source-sink pairs in which each vertex of G is covered by a path. In this paper, we investigate disjoint path covers in recursive circulants G($cd^m$,d) with $d{\geq}3$ and tori, and show that provided the number of faulty elements (vertices and/or edges) is f or less, every nonbipartite recursive circulant and torus of degree $\delta$ has a paired k-DPC for any f and $k{\geq}1$ with $f+2k{\leq}{\delta}-1$.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.1073-1081
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• 2018

In this study, an operational data set was analysed by establishing a path model to figure out the actual cause-effect relationship of a wastewater treatment plant (WWTP); in particular, for the effluent concentrations of T-N and T-P. To develop the path models, data sets of operational records including effluent concentrations and operational factors were obtained from a field scale WWTP of $680,000m^3$ of treatment capacity. The models showed that the relationship networks with the correlation coefficients between variables for objective expressions indicated the strength of each relationship. The suggested path models were verified according to whether the analyzation results matched known theories well, but sophisticated minute theoric relationships could not be cropped out distinctly. This indicates that only a few paths with strong theoric casual relationships were represented as measured data due to the high non-linearity of the mechanism of the removal process in a biological wastewater treatment.

• Journal of Korean Academy of Nursing
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• v.52 no.4
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• pp.363-377
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• 2022

Purpose: This study aimed to test a hypothetical model of Korean nurses' patient safety management activities using meta-analytic path analysis. Methods: A systematic review, meta-analysis, and meta-analytic path analysis were conducted following the PRISMA and MOOSE guidelines. Seventy-four studies for the meta-analysis and 92 for the meta-analytic path analysis were included. The R software program (Version 3.6.3) was used for data analysis. Results: Four variables out of 49 relevant variables were selected in the meta-analysis. These four variables showed large effect sizes (ESr = .54) or median effect sizes (ESr = .33~.40) with the highest k (number of studies) in the individual, job, and organizational categories. The hypothetical model for the meta-analytic path analysis was established using these variables and patient safety management activities. Twelve hypothetical paths were set and tested. Finally, the perception of the importance of patient safety management and patient safety competency directly affected patient safety management activities. In addition, self-efficacy, the perception of the importance of patient safety management, patient safety competency, and patient safety culture, indirectly affected patient safety management activities. Conclusion: Self-efficacy, the perception of the importance of patient safety management, patient safety competency, and the organization's patient safety culture should be enhanced to improve nurses' patient safety management activities.