• Journal of Korea Multimedia Society
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• v.24 no.11
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• pp.1538-1551
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• 2021

The current drone flight plan creation creates a flight path point of two-dimensional coordinates on the map and sets an arbitrary altitude value considering the altitude of the terrain and the possible flight altitude. If the created flight path is a simple terrain such as a mountain or field, or if the user is familiar with the terrain, setting the flight altitude will not be difficult. However, for drone flight in a city where buildings are dense, a safer and more precise flight path generation method is needed. In this study, using high-precision spatial information, we construct a drone safety flight map with a 3D grid map structure and propose a flight path search algorithm based on it. The safety of the flight path is checked through the virtual drone flight simulation extracted by searching for the flight path based on the 3D grid map created by setting weights on the properties of obstacles and terrain such as buildings.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12B
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• pp.1535-1541
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• 2009

In this paper, we suggest an efficient path searching algorithm that reduces the hop count when each node sends a data in ZigBee networks. As the hop count reduces, the network traffic is also reduces and leads to less energy consumption. This enables the sensor network live longer with limited node power. The proposed path searching algorithm consists of two sub-algorithms. One for upstream process and the other for downstream process. When a node selects its proper routing path, the node not only uses the information of the parent and child node, but it also uses the neighbor nodes for each node. In the simulation, we changed various network environment factors such as network parameters, number of nodes, and number of neighbor nodes and observed their performances. We compare the performance to the previous ZigBee Tree routing algorithm with separate two algorithms, the upstream and the downstream, and then compare the performance when all two algorithms are applied.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1986.04a
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• pp.142-145
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• 1986

The traffic characteristics of digital switch network depend on the structure, blocking probability, path searching method and etc. This paper presents the study of TDX-1 switch network traffic capacity by considering some decisive factors such as call processing software, switch network structure and control scheme. Conclusively the study shows that the switch network of TDX-1 can handle approximatly up to 1650 Erlang.

• The KIPS Transactions:PartD
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• v.11D no.7 s.96
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• pp.1409-1416
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• 2004

Recently, due to the popularity and explosive growth of the Internet, information exchange is increasing dramatically over the Internet. Also the XML is becoming a standard as well as a major tool of data exchange on the Internet. so that in retrieving the XML document. the problem for speeding up evaluation of path-oriented queries is a main issue. In this paper, we propose a new indexing technique to advance the searching performance of path-oriented queries in document databases. In the new indexing technique, an abbreviation-path file to perform path-oriented queries efficiently is generated which is able to use its hash-code value to index keys. Also this technique can be further enhanced by combining the Extendible Hashing technique with the abbreviation path file to expedite a speed up evaluation of retrieval.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.537-540
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• 2000

The Distribution System consist of many tie-line switches and sectionalizing switches, operated a radial type. When an outage occurs in Distribution System, outage areas are isolated by system switches, has to restored as soon as possible. At this time, system operator have to get a information about network topology for service restoration of outage areas. Therefore, the searching result of restorative topology has to fast computation time and reliable result topology for to restore a electric service to outage areas, equal to optimal switching operation problem. So, the problem can be defined as combinatorial optimization problem. The service restoration problem is so important problem which have outage area minimization, outage loss minimization. Many researcher is applying to the service restoration problem with various techniques. In this paper, advanced Dijkstra algorithm is applied to searching a restoration topology, is so efficient to searching a shortest path in graph type network. Additionally, fuzzy rules and operator are applied to overcome a fuzziness of correlation with input data. The present technique has superior results which are fast computation time and searching results than previous researches, demonstrated by example distribution model system which has 3 feeders, 26 buses. For a application capability to real distribution system, additionally demonstrated by real distribution system of KEPCO(Korea Electric Power Corporation) which has 8 feeders and 140 buses.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8A
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• pp.581-590
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• 2003

This paper proposes the routing path selection mechanism for source routing-based PtMP (Point-to-Multipoint) call in ATM switching system. Especially, it suggests PtMP routing path selection method that can share the maximum resource prior to the optimal path selection, guarantee the reduction of path calculation time and cycle prevention. The searching for the nearest branch point from destination node to make the maximum share of resource is the purpose of this algorithm. Therefore among neighbor nodes from destination node by back-tracking, this algorithm fixes the node crossing first the node on existing path having the same Call ID as branch node, constructs the optimal PtMP routing path. The optimal node to be selected by back-tracking is selected by the use of Dijkstra algorithm. That is to say, PtMP routing path selection performs the step of cross node selection among neighboring nodes by back-tracking and the step of optimal node selection(optimal path calculation) among neighboring nodes by back-tracking. This technique reduces the process of search of routing information table for path selection and path calculation, also solves the cycle prevention easily during path establishment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.1931-1938
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• 2012

A by-pass path in wireless sensor networks is the alternative path which be able to forward data when a routing path is being broken. One reason of depleting energy is occurred by the path. The method for solving prior to addressed the problem is proposed. However, this method may deplete radio resource. The best path has advantage that network lifetime of sensor nodes is prolonged; on the contrary, in order to maintain the best path it have to share their information between the entire nodes. In this paper, we propose the best path searching algorithm in the distributed three dimensional sensor networks. Through the neighboring informations sharing in the proposed method, the proposed algorithm can decide the best k-path as well as the extension of network lifetime.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.283-286
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• 1996

This study suggests a new methodology for the fault diagnosis based on the signed digraph in developing the fault diagnosis system of a boiler plant. The suggested methodology uses the new model, fault-effect tree. The SDG has the advantage, which is simple and graphical to represent the causal relationship between process variables, and therefore is easy to understand. However, it cannot handle the broken path cases arisen from data uncertainty as it assumes consistent path. The FET is based on the SDG to utilize the advantages of the SDG, and also covers the above problem. The proposed FET model is constructed by clustering of measured variables, decomposing knowledge base and searching the fault propagation path from the possible faults. The search is performed automatically. The fault diagnosis system for a boiler plant, ENDS was constructed using the expert system shell G2 and the advantages of the presented method were confirmed through case studies.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.3
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• pp.329-336
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• 2000

A method for automatic extraction of 2-dimensional finite element connectivities by searching the shortest closed path from a certain node to the starting node was developed. Only the best path among the possible paths was probed. The uniqueness and validity of the extracted path were examined. The proposed method was proved to be complete. Examples show that the proposed method can extract elements exactly from the irregular mesh which can not be handled easily by the conventional automatic mesh generation.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.479-483
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• 2015

In case of the big city, choosing the adequate root of which we can reach the destination can affect the driver's condition and driving time. so it is quite important to find the optimal routes for arriving the destination as considering the factors, such as driving conditions or travel time and so on. In this paper, we develop route choice model with considering driving conditions and travel time, and it can search the optimal path which make drivers reduce their fatigues using genetic algorithm.