• Journal of Intelligence and Information Systems
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• v.29 no.2
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• pp.101-114
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• 2023

In the wartime, aircraft carrying out a mission to strike the enemy deep in the depth are exposed to the risk of being shoot down. As a key combat force in mordern warfare, it takes a lot of time, effot and national budget to train military flight personnel who operate high-tech weapon systems. Therefore, this study studied the path problem of predicting the route of emergency escape from enemy territory to the target point to avoid obstacles, and through this, the possibility of safe recovery of emergency escape military flight personnel was increased. based problem, transforming the problem into a TSP, VRP, and Dijkstra algorithm, and approaching it with an optimization technique. However, if this problem is approached in a network problem, it is difficult to reflect the dynamic factors and uncertainties of the battlefield environment that military flight personnel in distress will face. So, MDP suitable for modeling dynamic environments was applied and studied. In addition, GIS was used to obtain topographic information data, and in the process of designing the reward structure of MDP, topographic information was reflected in more detail so that the model could be more realistic than previous studies. In this study, value iteration algorithms and deterministic methods were used to derive a path that allows the military flight personnel in distress to move to the shortest distance while making the most of the topographical advantages. In addition, it was intended to add the reality of the model by adding actual topographic information and obstacles that the military flight personnel in distress can meet in the process of escape and escape. Through this, it was possible to predict through which route the military flight personnel would escape and escape in the actual situation. The model presented in this study can be applied to various operational situations through redesign of the reward structure. In actual situations, decision support based on scientific techniques that reflect various factors in predicting the escape route of the military flight personnel in distress and conducting combat search and rescue operations will be possible.

• The Transactions of the Korea Information Processing Society
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• v.3 no.2
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• pp.242-250
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• 1996

Communications on hypercube nodes are done by explicit message routing. So efficient message routing is very important for the performance of hypercube multicomputers. However, hypercube nodes can be faulty due to hardware and/o r software problems, which is called an injured hypercube. A reliable hypercube system should tolerate the problems. One of the methods to enhance reliability on injured hypercube is to use fault-tolerant message routing algorithms. In this paper, we propose a message routing algorithm with possible shortest distance using disjoint paths. To analyze the performance, the algorithm is simulated and evaluated.

• Journal of The Korean Association of Information Education
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• v.20 no.1
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• pp.93-100
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• 2016

Computer Science Unplugged is a collection of free learning activities that teach Computer Science through engaging games and puzzles that use cards, string, crayons and lots of running around. In spite of the success of unplugged activities, the unplugged resources for experiencing the concepts of data structures is lacked. In this study, we design, implement and survey the 3 hour lessons of the core concepts of graph theory and the shortest path algorithm for the primary students using computer science unplugged activities. Our survey results showed that our lesson plan is adequate for primary school students and will have a positive effects for primary school students.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.11
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• pp.988-996
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• 2012

This paper presents a distributed task assignment algorithm for the suppression of enemy air defense (SEAD) mission of heterogeneous UAVs, based on the consensus-based bundle algorithm (CBBA). SEAD mission can be modeled as a task assignment problem of multiple UAVs performing multiple air defense targets, and UAVs performing SEAD mission consist of the weasel for destruction of enemy's air defense system and the striker for the battle damage assessment (BDA) or other tasks. In this paper, a distributed task assignment algorithm considering path-planning in presence of terrain obstacle is developed for heterogeneous UAVs, and then it is applied to SEAD mission. Through numerical simulations the performance and the applicability of the proposed method are tested.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.6
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• pp.1441-1446
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• 2014

For the escape from a maze, the cooperative method by robot swarm was proposed in this paper. The robots can freely move by collecting essential data and making a decision in the use of sensors; however, a central control system is required to organize all robots for the escape from the maze. The robots explore new mazes and then send the information to the system for analyzing and mapping the escaping route. Three issues were considered as follows for the effective escape by multiple robots from the mazes in this paper. In the first, the mazes began to divide and secondly, dead-ends should be blocked. Finally, after the first arrivals at the destination, a shortcut should be provided for rapid escaping from the maze. The parallel-escape algorithms were applied to the different size of mazes, so that robot swarm can effectively get away the mazes.

• KIPS Transactions on Computer and Communication Systems
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• v.1 no.2
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• pp.79-86
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• 2012

An economic ship routing means to sail a ship with a goal of minimizing the fuel consumption by utilizing weather forecast information, and various such systems have been recently studied. For a successful economic ship routing system, an efficient algorithm is needed to search an optimal geographical path, and most of the previous systems were approaching to that problem through a minimal static-cost path search algorithm based on the Dijkstra algorithm. To apply that kind of search algorithm, the cost of every edge assigned with the estimated fuel consumption should be constant. However, that assumption is not practical at all considering that the actual fuel consumption is determined by the weather condition when the ship will pass the edge. To overcome such a limitation, we propose a new optimal ship routing system based on a minimal dynamic-cost path search algorithm by properly modifying the Dijkstra algorithm. In addition, we propose a method which efficiently reduces the search space by using the $A^*$ algorithm to decrease the running time. We compared our system with the shortest path-based sailing method over ten testing routes and observed that the former reduced the estimated fuel consumption than the latter by 2.36% on average and the maximum 4.82% with little difference of estimated time of arrival.

• Korean Journal of Culture and Social Issue
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• v.29 no.4
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• pp.569-593
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• 2023

The purpose of this study was to investigate the mediating effects of rejection sensitivity in pathological narcissism and dating violence, and to verify whether there is a gender difference in each variable, further examining the gender difference in the mediating pathways. The participants of this study were 381 men and women in 20s living across the country, and online self-report surveys was conducted regarding their experiences of pathological narcissism, rejection sensitivity, and four types of dating violence. As a result of verifying gender differences, it was found that women had a higher vulnerability to narcissism, rejection sensitivity and committed more psychological violence, sexual violence, and controlling behavior than men. As a result of the mediation analysis, it was found that rejection sensitivity partial mediated the effect of pathological narcissism on psychological violence and control behavior, but it showed a complete mediation effect on sexual violence. And there was no mediating effect of rejection sensitivity between pathological narcissism and physical violence. As a result of measuring the moderating effect of gender in this mediating pathways, the moderated mediating effect of gender was verified in the effect of naricissistic grandiosity and narcissistic vulnerability on control behavior through rejection sensitivity. These results show that pathological narcissism promotes psychological and sexual violence in both men and women, and rejection sensitivity acts as a mediator in this process. In addition, the effect of pathological narcissism on the control behaviors through rejection sensitivity was significantly higher in women than in men, indicating that there are gender differences in the mediated pathways. Finally, the implications and limitations of this study and suggestions for follow-up studies were discussed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.211-218
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• 2015

This paper introduces a 'divide-and-conquer' algorithm to the travelling salesman problem (TSP). Top 10n are selected beforehand from a pool of n(n-1) data which are sorted in the ascending order of each vertex's distance. The proposed algorithm then firstly selects partial paths that are interconnected with the shortest distance $r_1=d\{v_i,v_j\}$ of each vertex $v_i$ and assigns them as individual regions. For $r_2$, it connects all inter-vertex edges within the region and inter-region edges are connected in accordance with the connection rule. Finally for $r_3$, it connects only inter-region edges until one whole Hamiltonian cycle is constructed. When tested on TSP-1(n=26) and TSP-2(n=42) of real cities and on a randomly constructed TSP-3(n=50) of the Euclidean plane, the algorithm has obtained optimal solutions for the first two and an improved one from that of Valenzuela and Jones for the third. In contrast to the brute-force search algorithm which runs in n!, the proposed algorithm runs at most 10n times, with the time complexity of $O(n^2)$.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.11
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• pp.603-609
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• 2003

Adaptive routing methods are studied for effective routing in many topologies where occurrence of the faulty nodes are inevitable. Mesh topology provides simplicity in implementing these methods. Many routing methods for mesh are able to tolerate a large number of faults enclosed by a rectangular faulty block. But they consider even good nodes in the faulty block as faulty nodes. Hence, it results the degradation of node utilization. This problem is solved by a method which transmits messages to destinations within faulty blocks via multiple “intermediate nodes”. It also divides faulty block into multiple expanded meshes. With these expanded meshes, DAG(Directed Acyclic Graph) is formed and a message is able to be routed by the shortest path according to the DAG. Therefore, the additional number of hops can be resulted. We propose a method that reduces the number of hops by searching direct paths from the destination node to the border of the faulty block. This path is called SCP(Short-Cut Path). If the path and the traversing message is on the same side of outside border of the faulty block, the message will cut into the path found by our method. It also reduces the message traverse latency between the source and the destination node.

• Journal of Intelligence and Information Systems
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• v.11 no.1
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• pp.153-167
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• 2005

In this paper, we consider the problem of exploring unknown environments with a mobile robot or an autonomous character agent. Traditionally, research efforts to address the space exploration problem havefocused on the graph-based space representations and the graph search algorithms. Recently EXPLORE, one of the most efficient search algorithms, has been discovered. It traverses at most min$min(mn, d^2+m)$ edges where d is the deficiency of a edges and n is the number of edges and n is the number of vertices. In this paper, we propose DFS-RTA* and DFS-PHA*, two real-time graph search algorithms for directing an autonomous agent to explore in an unknown space. These algorithms are all built upon the simple depth-first search (DFS) like EXPLORE. However, they adopt different real-time shortest path-finding methods for fast backtracking to the latest node, RTA* and PHA*, respectively. Through some experiments using Unreal Tournament, a 3D online game environment, and KGBot, an intelligent character agent, we analyze completeness and efficiency of two algorithms.