• Journal of Communications and Networks
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• v.14 no.6
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• pp.662-671
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• 2012

Plug-in hybrid electric vehicles (PHEVs) will be widely used in future transportation systems to reduce oil fuel consumption. Therefore, the electrical energy demand will be increased due to the charging of a large number of vehicles. Without intelligent control strategies, the charging process can easily overload the electricity grid at peak hours. In this paper, we consider a smart charging and discharging process for multiple PHEVs in a building's garage to optimize the energy consumption profile of the building. We formulate a centralized optimization problem in which the building controller or planner aims to minimize the square Euclidean distance between the instantaneous energy demand and the average demand of the building by controlling the charging and discharging schedules of PHEVs (or 'users'). The PHEVs' batteries will be charged during low-demand periods and discharged during high-demand periods in order to reduce the peak load of the building. In a decentralized system, we design an energy cost-sharing model and apply a non-cooperative approach to formulate an energy charging and discharging scheduling game, in which the players are the users, their strategies are the battery charging and discharging schedules, and the utility function of each user is defined as the negative total energy payment to the building. Based on the game theory setup, we also propose a distributed algorithm in which each PHEV independently selects its best strategy to maximize the utility function. The PHEVs update the building planner with their energy charging and discharging schedules. We also show that the PHEV owners will have an incentive to participate in the energy charging and discharging game. Simulation results verify that the proposed distributed algorithm will minimize the peak load and the total energy cost simultaneously.

• Journal of Digital Convergence
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• v.15 no.9
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• pp.415-425
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• 2017

The purpose of this study is to examine the effect of perceived enjoyment and user's characteristics on the intention of continuous use when users play social network games on a mobile device. In addition, the study empirically investigated the mediating effect of flow experience in this process. To fulfill the purpose, this study conducted a survey on 244 college students and collected data. When the collected data was analyzed, the followings were known. First, perceived enjoyment, and both self-efficacy and innovation propensity of user's characteristics turned out to have a positive (+) effect on the intention of continuous use in mobile social network game. Second, in the process, it was known that flow experience played a mediating role. These findings are expected to be useful data in developing game contents of high quality or making a marketing strategy for continuous improvement of online social network game industry. In addition, future studies are expected to generalize the research to various age groups.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.423-431
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• 2016

Customizing system is known as an important factor which affects not only purchase, loyalty and immersion of the user. In this study, we explore the concept of character-customizing system in the early stage of a game; on the basis of it, we compare cases by analyzing and schematizing certain types of systems which many games stick to. Customizing system types are divided into a basic case and a differentiated convergence case; based on it, they are classified into four types: Realistic, Creation, Individual, Additional; plus, another customizing system case out of games is also analyzed. To improve customer loyalty, a system like a differentiated case that attracts user participation is essential. Through a variety of character customization convergence cases shown in this study, we expect them to be used as game production guides. By enlarging the range of the study, we expect further studies to cover more cases.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.738-747
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• 2021

Space and place have distinctively different meanings from each other. As virtual reality has become a routine of daily life, placeness concepts have been introduced on discussion tables. Yet, place has not been widely discussed in conceptual approaches Thus, using the concepts of space and place this study attempts to figure out the structure and the processes of how users recognize digital space and give placeness. For the study purpose, it identifies core elements of placeness attribution in digital game places, and then explains the development processes of space into place through characteristics of MDA(Mechanics-Dynamics-Aesthetics)framework. Based on present theoretical concepts and their application process this study also demonstrates the transformation process through which physical space becomes a place in the similar context with a necessary condition in order for a space to be a place. This study confirms that digital games can be transformed into a space that creates placeness in the process. Considering that players' affinity and nostalgia are generated through the placeness acquiring process in digital game space, the processes eventually imply an extension of largely meaningful and influencing contents as digital games induce players' immersion.

• Journal of Korea Multimedia Society
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• v.13 no.12
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• pp.1820-1831
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• 2010

When interacting with unknown environments, an autonomous agent needs to decide which action or action order can result in a good state and determine the transition probability based on the current state and the action taken. The traditional multiple sequential learning model requires predefined probability of the states' transition. This paper proposes a multiple sequential learning and prediction system with definition of autonomous states to enhance the automatic performance of existing AI algorithms. In sequence learning process, the sensed states are classified into several group by a set of proposed motivation filters to reduce the learning computation. In prediction process, the learning agent makes a decision based on the estimation of each state's cost to get a high payoff from the given environment. The proposed learning and prediction algorithms heightens the automatic planning of the autonomous agent for interacting with the dynamic unknown environment. This model was tested in a virtual library.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.541-546
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• 2009

There are many videos about sports. There is a large need for content based video retrievals. In sports videos, the motions and camera works have much information about shots and plays. This paper proposes the baseball game process understanding using the similar motion retrieval on videos. We can retrieve the similar motion parts based on motions shown in videos using the space-time images describing the motions. Using a finite state model of plays, we can decide the precise point of pitches from the pattern of estimated typical motions. From only the motions, we can decide the precise point of pitches. This paper describes the method and the experimental results.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1763-1768
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• 2003

Current trend of design technologies shows engineers to objectify or automate the given decision-making process. The numerical optimization is an example of such technologies. However, in numerical optimization, the uncertainties are uncontrollable to efficiently objectify or automate the process. To better manage these uncertainties, Taguchi method, reliability-based optimization and robust optimization are being used. Based on the independence axiom of axiomatic design theory that illustrates the relationship between desired specifications and design parameters, the designs can be classified into three types: uncoupled, decoupled and coupled. To best approach the target performance with the maximum robustness is one of the main functional requirements of a mechanical system. Most engineering designs are pertaining to either coupled or decoupled ones, but these designs cannot currently accomplish a real robustness thus a trade-off between performance and robustness has to be made. In this research, the game theory will be applied to optimize the trade-off.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2004.11a
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• pp.80-83
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• 2004

It is impossible to do real verification on design spaces before their completions due to the characteristics of building and interior space designs. So, in designing spaces, designers should reflect their real experiences in their lives into their design works. 3D games where GPU and other kinds of advanced technologies have bee applied first show their leads in technologies have bee applied first show their leads in technologies about 5 years than VRML. Those games which are produced reflecting real environment as it is could be regarded as the most excellent tool in their completeness level of physical environment due to their characteristics. This means that if 3D game engines employing GPU are used effectively they could be used as a presentation tool for virtual spaces. This study studies the expressions of virtual constructions through 3D game engines employing GPU, not in VRML-based virtual spaces on Webs but in immersion-type virtual spaces.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.07a
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• pp.113-114
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• 2012

게임이 기획, 그래픽, 프로그램의 복합적 기능을 가진 콘텐츠이지만 특별히 수준 높은 그래픽 데이터는 이용자의 만족도, 몰입 등에 긍정적인 영향을 미치는 중요한 영역이다. 그러나 아직 국내외에 게임 그래픽 데이터의 품질을 객관적으로 평가할 수 있는 기준이 마련되어 있지 않다. 이에 따라 본 논문에서는 게임 그래픽 데이터의 품질 평가를 위한 지표를 개발하는 프로세스를 제안한다. 제안된 프로세스는 그래픽 데이터의 품질 평가 영역 추출을 위한 방법과 세부 평가 지표 마련을 위한 평가 항목 추출방법들로 구성된다. 본 연구 결과는 고품질 게임 개발을 위한 품질평가 지표 개발에 적용될 것이며 관련 분야의 품질평가 모델 개발의 참조 모델이 될 것이다. 향후 본 연구는 국내외 게임 그래픽 데이터의 품질평가 표준안 설계 개발로 진행될 예정이다.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.6
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• pp.802-811
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• 2012

This study proposes an OMS/MP preparation methodology using a simulation method instead of a survey method. We applied our methodology to the next generation detection radar, providing reasonable peace- and war-time OMS/MP values. Based on these results, we propose the process to calculate RAM objective values. The previous survey method required to supplement its method since the method used data from a similar weapon system. In addition, the previous method didn't provide enough reliability for the future weapon system. Instead of using the previous survey method, we propose to use war game simulation, which provides a better OMS/MP values. Based on these results, we propose the logical consecutive process that prepares combat and simulation scenarios, peace- and war-time OMS/MP values and RAM objective values.