• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.2
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• pp.33-39
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• 2015

Power supplying capacity of the distribution feeder should be maintained within thermal capacity of the wire. This paper presents the minimum spanning tree based load balancing technique to release multiple overloading of distribution feeders. In order to minimize number of involved backup feeders, Dijkstra and Prim algorithm are adopted to construct minimum spanning tree. Simulation testing result based on part of KEPCO's commercial distribution systems shows effectiveness of proposed scheme.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.617-623
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• 2023

Among the fire incidents in Korea over the past decade, building fires are the most common, and property and human casualties are the most common. However, the existing fire fighting system does not only inform the location of emergency exits and guide safe routes to help casualties evacuate smoothly. A system was proposed to help successful evacuation by distinguishing vertical and horizontal characteristics using spatial characteristics. In this study, an effective evacuation system was proposed by predicting fires using temperature detection sensors and smoke sensor values, and calculating the optimal evacuation path through the Dijkstra algorithm.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.05a
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• pp.38-39
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• 2019

Optimal route planning is the route planning to minimize voyage time or fuel consumption in a given ocean environment. Unlike the previous studies on weather routing, this study proposes an optimization method for the route planning to avoid the grounding risk in the coast. The route way-points were searched using Dijkstra algorithm, and then the optimization was performed to minimize fuel consumption by setting the optimization design parameter to the engine rpm. To set the engine rpm, a method to use the fixed rpm from the departure point to the destination point, and a method to use the rpm for each section by dividing the route were used. The ocean environmental factors considered for route planning were wind, wave, and current, and the depth information was utilized to compute grounding risk. The proposed method was applied to the ship passing between Mokpo and Jeju, and then it was confirmed that fuel consumption was reduced by comparing the optimum route and the past navigated route.

• Journal of Korean Society of Transportation
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• v.21 no.2
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• pp.71-82
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• 2003

The shortest path problems(SPP) are critical issues in the military logistics such as the simulation of the War-Game. However, the existing SPP has two major drawbacks, one is its accuracy of solution and the other is for only one solution with focused on just link cost in the military transportation planning models. In addition, very few previous studies have been examined for the multi-shortest path problems without considering link capacity reflecting the military characteristics. In order to overcome these drawbacks, it is necessary to apply the multi-shortest paths algorithm reflecting un-expected military incidents. This study examines the multi-shortest paths in the real networks using Shier algorithm. The network contains both military link capacity and time-based cost. Also, the modes are defined as a platoon(group) rather than unit which is used in most of previous studies in the military logistics. To verify the algorithm applied in this study. the comparative analysis was performed with various sizes and routes of network which compares with Dijkstra algorithm. The major findings of this study are as follows ; 1) Regarding the unique characteristics of the military transportation plan, Shier algorithm, which is applied to this study, is more realistic than Dijkstra algorithm. Also, the time based concept is more applicable than the distance based model in the military logistics. 2) Based on the results from the various simulations of this study the capacity-constraint sections appeared in each scenarios. As a consequence, the alternatives are necessary such as measures for vulnerable area, improvement of vehicle(mode), and reflection of separated-marching column in the military manuals. Finally. the limits and future research directions are discussed : 1) It is very hard to compare the results found in this study. which is used in the real network and the previous studies which is used in arbitrary network. 2) In order to reflect the real military situations such as heavy tanks and heavy equipment vehicles. the other constraints such as the safety load of bridges and/or the height of tunnels should be considered for the future studies.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.11B
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• pp.991-1000
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• 2004

This paper presents an application layer multicast tree constructing algorithm to minimize the average time delay from the sender to end-systems for the effective real-time media delivery. Simultaneously, the proposed algorithm takes into account the computing power and the network condition of each end-system as a control variable and thus avoids the undesirable case that loads are concentrated to only several end-systems. The multicast tree is constructed by clustering technique and modified Dijkstra's algorithm in two steps, i.e. tree among proxy-senders and tree in each cluster. By the experimental results, we show that the proposed algorithm can provide an effective solution.

• Journal of Korean Society of Transportation
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• v.13 no.3
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• pp.35-52
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• 1995

This paper reviews both network representation schemes of transportation network and algorithms for findings the shortest path between two points in the network. Two types of network representation schmes for considering U-Turn have been proposed along with some modifications of the vine-based Dijkstra shoretest path algorithm. The traditional Sioux-Fall network has been chosen and modified with the introduction of left-turn prohibitions and U-Turns for the purpose of evaluating the peroformance of two modified algorithms and network representation schemes(NA1 an d NA2 ). This type of modification in both network representation scheme (including network data) and algorithms is not only supposed to be needed for route guidance but supposed to contribute to finding more realistic path and estimating more accurate traffic voulume thorughout the entire network.

• 한국ITS학회:학술대회논문집
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• 2004.11a
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• pp.343-348
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• 2004

• Korean Management Science Review
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• v.25 no.2
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• pp.81-88
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• 2008

This paper presents a new algorithm for the K shortest paths problem in a network. After a shortest path is produced with Dijkstra algorithm. detouring paths through inward arcs to every vertex of the shortest path are generated. A length of a detouring path is the sum of both the length of the inward arc and the difference between the shortest distance from the origin to the head vertex and that to the tail vertex. K-1 shorter paths are selected among the detouring paths and put into the set of K paths. Then detouring paths through inward arcs to every vertex of the second shortest path are generated. If there is a shorter path than the current Kth path in the set. this path is placed in the set and the Kth path is removed from the set, and the paths in the set is rearranged in the ascending order of lengths. This procedure of generating the detouring paths and rearranging the set is repeated until the $K^{th}-1$ path of the set is obtained. The computational results for networks with about 1,000,000 nodes and 2,700,000 arcs show that this algorithm can be applied to a problem of generating the detouring paths in the metropolitan traffic networks.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.11a
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• pp.60-66
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• 2006

This paper presents a new algorithm for the K shortest path problem in a directed network. After a shortest path is produced with Dijkstra algorithm, detouring paths through inward arcs to every vertex of the shortest path are generated. A length of a detouring path is the sum of both the length of the inward arc and the difference between the shortest distance from the origin to the head vertex and that to the tail vertex. K-1 shorter paths are selected among the detouring paths and put into the set of K paths. Then detouring paths through inward arcs to every vertex of the second shortest path are generated. If there is a shorter path than the current Kth path in the set, this path is placed in the set and the Kth path is removed from the set, and the paths in the set is rearranged in the ascending order of lengths. This procedure of generating the detouring paths and rearranging the set is repeated for the K-1 st path of the set. This algorithm can be applied to a problem of generating the detouring paths in the navigation system for ITS and also for vehicle routing problems.

• Journal of the Korean Operations Research and Management Science Society
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• v.26 no.3
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• pp.79-94
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• 2001

This paper presents a new algorithm for the K shortest paths Problem which develops initial K shortest paths, and repeat to expose hidden shortest paths with dual approach and to replace the longest path in the present K paths. The initial solution comprises K shortest paths among shortest paths to traverse each arc in a Double Shortest Arborescence which is made from bidirectional Dijkstra algorithm. When a crossing node that have two or more inward arcs is found at least three time by turns in this K shortest paths, there may be some hidden paths which are shorter than present k-th path. To expose a hidden shortest path, one inward arc of this crossing node is chose by means of minimum detouring distance calculated with dual variables, and then the hidden shortest path is exposed with joining a detouring subpath from source to this inward arc and a spur of a feasible path from this crossing node to sink. If this exposed path is shorter than the k-th path, the exposed path replaces the k-th path. This algorithm requires worst case time complexity of O(Kn$^2$), and O(n$^2$) in the case k$\leq$3.