• Journal of Korean Society of Rural Planning
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• v.19 no.4
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• pp.177-189
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• 2013

3D modeling and rendering technologies are getting more attention from landscape planners and architects because the virtual reality based on 3D graphic technology could give more realistic experience to landscape simulation users and boost promotional effects. The 3D landscape simulation, however, not only requires a lot of cost and time in production, but also demands efforts to distribute to consumers due to various computing environment of them. The purpose of this study is to suggest a process for developing an interactive 3D landscape simulator with low-cost, which can support multi-platform functionality in high quality through reviewing related current software and web services. We select GIMP for 2D image texturing, SketchUpfor 3D modeling, Unity for real-time rendering, and Google Earth for terrain modeling considering price and workability and apply the developed process for Windows, Web, and Android versions to test the applicability for Sangji-ri, Gosam-myeon, Gyeonggi-do, Korea.

• Journal of Korea Game Society
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• v.17 no.4
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• pp.55-62
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• 2017

In this study, motion simulation of Walk-through was evaluated with HMD(Head Mounted Display). More Specifically, we examined the changes of the degree of object density placed around virtual space on psychological moving distance, moving speed, and moving time. The results were as follows. First, the difference between the experimental conditions(low density, Medium density, High density) was significant. Second, as the density of the surrounding objects increased, the average point of moving time, moving speed, and moving distance rose compared to the basic conditions. Third, it was found that the surrounding objects improved the sense of time, speed and distance in motion simulation in virtual space.

• Journal of the Korea Society for Simulation
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• v.14 no.3
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• pp.21-31
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• 2005

In state-of-the-art games, characters can move in a goal-directed manner so that they can move to the goal position without colliding obstacles. Many path-finding methods have been proposed and implemented for these characters and most of them use the A* search algorithm. When .the map is represented with a regular grid of squares or a navigation mesh, it often takes a long time for the A* to search the state space because the number of cells used In the grid or the mesh increases for higher resolution. Moreover the A* search on the grid often causes a zigzag effect, which is not optimal and realistic. In this paper we propose to use visibility graphs to improve the search time by reducing the search space and to find the optimal path. We also propose a method of taking into account the size of moving characters in the phase of planning to prevent them from colliding with obstacles as they move. Simulation results show that the proposed method performs better than the grid-based A* algorithm in terms of the search time and space and that the resulting paths are more realistic.

• Journal of Korea Game Society
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• v.9 no.5
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• pp.25-41
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• 2009

The objective of this study is to develop an analytic framework to code systematically the gamer's behaviour in MMO(Massively Multi-player Online) gameplay experience, to explore their gameplay as a problem solving procedure empirically. Previous studies about model human processor, content based protocol, and procedure based protocol are reviewed in order to build the outline of the analytic framework related to MMO gameplay. The specific gameplay actions and contents were derived by using concurrent protocol analysis method through the empirical experiment executed in MMORPG gameplay. Consequently, gameplay are divided into six actions : kinematics, perception, function, representation, simulation, and rule (heuristics, following, and transcedence). The analytic framework suitable for MMO gameplay was built. As a result of this study, we found three rule spaces in the problem solving domain of gameplay that are an heuristics, a following of the rule, and a transcendence of the rule. 'Heuristics' denotes the rule action that discovers the rule of game through trial-and-error. 'Following' indicates the rule action that follows the rule of game embedded in game by game designers. 'Transcendence' presents the rule action that transcends that. The new discovered rule spaces where 'Following' and 'Transcendence' actions occur and the gameplay pattern in them is provided with the key basis to determine the level design elements of MMO game, such as terrain feature, monster attribute, item, and skill et cetera. Therefore, this study is concludes with key implications to support game design to improve the quality of MMO game product.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.3
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• pp.253-261
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• 2004

Game theory is mathematical analysis developed to study involved in making decisions. In 1928, Von Neumann proved that every two-person, zero-sum game with finitely many pure strategies for each player is deterministic. As well, in the early 50's, Nash presented another concept as the basis for a generalization of Von Neumann's theorem. Another central achievement of game theory is the introduction of evolutionary game theory, by which agents can play optimal strategies in the absence of rationality. Not the rationality but through the process of Darwinian selection, a population of agents can evolve to an Evolutionary Stable Strategy (ESS) introduced by Maynard Smith. Keeping pace with these game theoretical studies, the first computer simulation of co-evolution was tried out by Hillis in 1991. Moreover, Kauffman proposed NK model to analyze co-evolutionary dynamics between different species. He showed how co-evolutionary phenomenon reaches static states and that these states are Nash equilibrium or ESS introduced in game theory. Since the studies about co-evolutionary phenomenon were started, however many other researchers have developed co-evolutionary algorithms, in this paper we propose Game theory based Co-Evolutionary Algorithm (GCEA) and confirm that this algorithm can be a solution of evolutionary problems by searching the ESS.To evaluate newly designed GCEA approach, we solve several test Multi-objective Optimization Problems (MOPs). From the results of these evaluations, we confirm that evolutionary game can be embodied by co-evolutionary algorithm and analyze optimization performance of GCEA by comparing experimental results using GCEA with the results using other evolutionary optimization algorithms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.6
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• pp.1379-1397
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• 2013

We consider a system where a licensed radio spectrum is shared by multiple primary users(PUs) and secondary users(SUs). As the spectrum of interest is licensed to primary network, power and channel allocation must be carried out within the cognitive radio network so that no excessive interference is caused to PUs. For this system, we study the joint beamforming and power allocation problem via game theory in this paper. The problem is formulated as a non-cooperative beamforming and power allocation game, subject to the interference constraints of PUs as well as the peak transmission power constraints of SUs. We design a joint beamforming and power allocation algorithm for maximizing the total throughput of SUs, which is implemented by alternating iteration of minimum mean square error based decision feedback beamforming and a best response based iterative power allocation algorithm. Simulation results show that the algorithm has better performance than an existing algorithm and can converge to a locally optimal sum utility.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.6
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• pp.2697-2710
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• 2018

Owing to the development of Internet of Things (IoT), the fifth-generation (5G) wireless communication is going to foresee a substantial increase of mobile traffic demand. Energy efficiency and spectral efficiency are the challenges in a 5G network. Non-orthogonal multiple access (NOMA) is a promising technique to increase the system efficiency by adaptive power control (PC) in a 5G network. This paper proposes an efficient PC scheme based on evolutionary game theory (EGT) model for uplink power-domain NOMA system. The proposed PC scheme allows users to adaptively adjusts their transmit power level in order to improve their payoffs or throughput which results in an increase of the system efficiency. In order to separate the user signals, a successive interference cancellation (SIC) receiver installed at the base station (BS) site. The simulation results demonstrate that the proposed EGT-based PC scheme outperforms the traditional game theory-based PC schemes and orthogonal multiple access (OMA) in terms of energy efficiency and spectral efficiency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.4
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• pp.785-794
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• 2009

We studied on a technic to improve and implement the virtual environment grid information in the war-game model. The virtual environment data are categorized into ground, sea, and air, and separatedly managed and operated. The data are implemented and managed in the geographical information and topography type information. The geographical information, including grid location coordinate and sea level, are managed in computer files as a grid type. We improved the representation of the sea level by mapping the sea level value of the grid information file into GCV and suggested the dynamic virtual environment implementation technic for the region with the large range of tide. In the experiments, we could know that it is possible to adopt the dynamic virtual environment to the war-game model.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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• pp.5820-5834
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• 2017

This paper investigates the channel selection problem with dynamic users and the asymmetric interference relation in distributed opportunistic spectrum access systems. Since users transmitting data are based on their traffic demands, they dynamically compete for the channel occupation. Moreover, the heterogeneous interference range leads to asymmetric interference relation. The dynamic users and asymmetric interference relation bring about new challenges such as dynamic random systems and poor fairness. In this article, we will focus on maximizing the tradeoff between the achievable utility and access cost of each user, formulate the channel selection problem as a directional graphical game and prove it as an exact potential game presenting at least one pure Nash equilibrium point. We show that the best NE point maximizes both the personal and system utility, and employ the stochastic learning approach algorithm for achieving the best NE point. Simulation results show that the algorithm converges, presents near-optimal performance and good fairness, and the directional graphical model improves the systems throughput performance in different asymmetric level systems.

• Journal of Aerospace System Engineering
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• v.14 no.2
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• pp.36-43
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• 2020

Many countries and international organizations have carried out rover missions to explore planetary surfaces. Accordingly, the demand for mechatronics education, which is closely related to building exploratory robots, is also steadily increasing. However, due to the complexity in understanding the background information needed for mechatronics, it is hard for pre-college students to study such process. In this study, we suggest an educational platform for mechatronics using a combined robot kit with a spherical robot and a smartphone application. To provide a visual understanding, the dynamic model of the robot is constructed while analyzing the error between actual driving and a simulation, and the educational algorithm of the game and a feedback method are proposed to improve the learning efficacy by considering the user's level of knowledge of mechatronics. We use this educational spherical robot to develop a curling game platform that can impart engineering education even when students lack significant knowledge.