• Geomechanics and Engineering
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• v.33 no.6
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• pp.529-542
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• 2023

Wave propagation with high transverse deflection could affect the stability of the ball in its trajectory. For low stiffness balls similar to soccer and volleyball balls, the waves are more noticeable in comparison to other balls like ping-pong ball. On the other hand, the soccer balls are under heavy impact loads from shoots and contacting different objects in the field. The maximum recorded speed of a soccer ball after kicking is the 211 km/hr and the average maximum speed is around 112 km/hr. Therefore, in such speeds the aerodynamic forces become important which are directly related to geometrical shape of the ball. In this regard, the wave propagation in soccer ball is examined in the current study using large deformation shear deformable formulations. Classical relations of stress-strain components are taken into consideration along with minimum total energy principle. The final derived relations were solved by using harmonic differential quadrature method. The results are generally presented ion term of phase velocity as function of different influencing parameters of the materials, geometry and mass of the ball.

• Journal of the Korean Mathematical Society
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• v.54 no.4
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• pp.1121-1148
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• 2017

Go is an ancient game of great complexity and has a huge following in East Asia. It is also very rich mathematically, and can be played on any graph, although it is usually played on a square lattice. As with any game, one of the most fundamental problems is to determine the number of legal positions, or the probability that a random position is legal. A random Go position is generated using a model previously studied by the author, with each vertex being independently Black, White or Uncoloured with probabilities q, q, 1 - 2q respectively. In this paper we consider the probability of legality for two scenarios. Firstly, for an $N{\times}N$ square lattice graph, we show that, with $q=cN^{-{\alpha}}$ and c and ${\alpha}$ constant, as $N{\rightarrow}{\infty}$ the limiting probability of legality is 0, exp($-2c^5$), and 1 according as ${\alpha}$ < 2/5, ${\alpha}=2/5$ and ${\alpha}$ > 2/5 respectively. On the way, we investigate the behaviour of the number of captured chains (or chromons). Secondly, for a random graph on n vertices with edge probability p generated according to the classical $Gilbert-Erd{\ddot{o}}s-R{\acute{e}}nyi$ model ${\mathcal{G}}$(n; p), we classify the main situations according to their asymptotic almost sure legality or illegality. Our results draw on a variety of probabilistic and enumerative methods including linearity of expectation, second moment method, factorial moments, polyomino enumeration, giant components in random graphs, and typicality of random structures. We conclude with suggestions for further work.

• Korean Journal of Applied Biomechanics
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• v.17 no.2
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• pp.177-185
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• 2007

Even though there were no clear definitions of the short game and short game distance, short game capability is crucial for a good golf score. Generally, chip shot and pitch shot are regarded as two principal components of the short game. Chip shot is a short, low trajectory shot played to the green or from trouble back into play. Pitch shot is a high trajectory shot of short length. Biomechanical studies were conducted usually to analyze full swing and putting motions. The purpose of the study was to reveal the kinematical differences between professional golfers' 30 yard $53^{\circ}wedge$ chip shot and $56^{\circ}wedge$ pitch shot motions. Fifteen male professional golfers were recruited for the study. Kinematical data were collected by the 60 Hz three-dimensional motion analysis system. Statistical comparisons were made by paired t-test, ANOVA, and Duncan of the SPSS 12.0K with the $\alpha$ value of .05. Results show that both the left hand and the ball were placed left of the center of the left and right foot at address. The left hand position of the chip shot was significantly left side of that of the pitch shot. But the ball position of the pitch shot was significantly right side of that of the chip shot. All body segments aligned to the left of the target line, open, at address. Except shoulder, there were no significant pelvis, knee, and feet alignment differences between chip shot and pitch shot. These differences at address seem for the ball height control. Pitch shot swing motions(the shoulder and pelvis rotation and the club head travel distance) were significantly bigger than those of the chip shot. Club head velocity of the pitch shot was significantly faster than that of the chip shot at the moment of impact. This was for the same shot length control with different lofted clubs. Swing motion differences seem mainly caused by the same shot length control with different ball height control.

• The KIPS Transactions:PartB
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• v.11B no.1
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• pp.83-90
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• 2004

Strategic games are missing special qualities of genre these days. Game engines neither reason about behaviors of computer objects nor have learning ability that can prepare countermeasure in variously command user's strategy. This paper suggests a strategic game engine that applies non-monotonic reasoning and inductive machine learning. The engine emphasizes three components -“user behavior monitor”to abstract user's objects behavior,“learning engine”to learn user's strategy,“behavior display handler”to reflect abstracted behavior of computer objects on game. Especially, this paper proposes two layered-structure to apply non-monotonic reasoning and inductive learning to make behaviors of computer objects that learns strategy behaviors of user objects exactly, and corresponds in user's objects. The engine decides actions and strategies of computer objects with created information through inductive learning. Main contribution of this paper is that computer objects command excellent strategies and reveal differentiation with behavior of existing computer objects to apply non-monotonic reasoning and inductive machine learning.

• (The)Study of the Eastern Classic
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• no.68
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• pp.509-538
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• 2017

After 20thcentury, digital game has placed very important aspect in modern culture and industries. Thus, digital game industries have utilized ancient stories for themes and ideas. This trial is not only spotted in industrial sectors but also in liberal arts. This paper has a purpose to look at factors that can convert components from classic novels into digital games. Especially, it will focus on how researchers of classical literature can affect in different industrial sectors. Current analysis shows that stories, fantasies, items of classic novel can essentially help to create new games. However, a game consists of just more than the previous stated components; it requires rules, outcome, conflicts and voluntary to make the games much more interesting. It is often misunderstood that plot and fantasies in games may be the most significant aspects but they are actually not. Classic novel can help to make the rule of the four standards in creating a fun game. Here are rules that Taewonji suggests. First, gamers need to save the bleak world from a turbulent age. Second, The will of the absolute has the ultimate power, so those who have achieved god's will can raise a new country. Thirdly, the sinocentrism and the outskirts of the country are not imperative but they are adjustable notions. The first and second aspects are commonly found in Samkukjiyeonui. Hence, the pattern is very familiar. The most significant rule is the third determinant since the idea purely came from Taewonji. The main character Im Seong from the story was the center of his home country, but he later becomes the outskirt or the barbarian of the new country. Therefore, the players should maintain the three rules when they are following the plot and using different items in the digital game world. The researchers of classic literature should find rules that are suitable for the game from the classic novels. This way, there is no need to discover a separate field for digital games out of classical literature.

• Archives of design research
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• v.20 no.1 s.69
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• pp.263-272
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• 2007

On-line game gradually grew into a significant part in Korean culture due to rapid development of internet. As icons are utilized as interface, the concept of UI(User Interface) receives spotlight in playing games, and the play bug appears most frequently in MMORPG genre. The introduction of icons brought partial inefficiency in dividing screen sectors while playing games, which means play sector is reduced. On the meantime, components of UI possess different places so that cause considerable confusion to heavy users. This study attempts to analyze the top 5 commonly-played games and to understand the necessity and status of UI components by surveying heavy users. The result of this study shows that there is notable difference between UI of games on-service and preference of heavy users. This study could suggest UI of a better quality by restructuring and rearranging the UI components based on the heavy users' preference as shown in the survey. It is expected that this study can contribute to creating a more effective game play by eliminating possible changes of UI upon different games and realizing broader play sector.

• Journal of Korea Multimedia Society
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• v.9 no.12
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• pp.1596-1606
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• 2006

There has been more increased the development of 3D technique since many 3D contents of 3D graphic model, 3D mobile/computer game, and 3D CAD have been serviced in Web or industry fields. Therefore, the watermarking system is more required to protect the copyright for 3D contents. Currently there has been researched about the watermarking for 3D graphic model of mesh or NURBS. However, watermarking technique based on CAD design drawing leaves something to be desired yet. This paper proposed the watermarking technique for 3D CAD design drawing using Line and Arc components. After drawing out Line and Arc components from designed drawing, we embed the watermark into both the length of Line component and the radius of Arc component. Experimental results verified that the proposed algorithm satisfies the transparency about watermarked drawing and also has the robustness against several attacks by using public CAD tool.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.456-464
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• 2017

These days, the sports industry and related industries are growing very fast due to active sports participation. Recently, tourism products that integrate tourism with sport have already appeared. The products include tourism behavior, such as sports activities, sports spectating, and visiting sports memorial halls and museums, etc. This study examined the relationship among the tourist behavior, sports spectating factors, and team association components. Based on the theoretical study, a field survey was performed by questionnaires. The sports spectating factors and team association components have a slight influence on the tourist behavior after analysis using the SPSS program. The implications are as follows. First, sports teams should make efforts not only on the team's win at the sports game, but also to develop marketing strategies about the sports complex, and star players of their team. Second, sports teams have to develop tourist products that collaborate with the local tourism industry linked to tourist attractions, accommodations, souvenir shop, and entertainment facilities for sports spectators.

• Journal of Astronomy and Space Sciences
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• v.19 no.2
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• pp.107-122
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• 2002

Multi-body spacecraft attitude and configuration control formulations based on the use of collaborative control theory are considered. The control formulations are based on two-player, nonzero-sum, differential game theory applied using a Nash strategy. It is desired that the control laws allow different components of the multi-body system to perform different tasks. For example, it may be desired that one body points toward a fixed star while another body in the system slews to track another satellite. Although similar to the linear quadratic regulator formulation, the collaborative control formulation contains a number of additional design parameters because the problem is formulated as two control problems coupled together. The use of the freedom of the partitioning of the total problem into two coupled control problems and the selection of the elements of the cross-coupling matrices are specific problems ad-dressed in this paper. Examples are used to show that significant improvement in performance, as measured by realistic criteria, of collaborative control over conventional linear quadratic regulator control can be achieved by using proposed design guidelines.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.2027-2030
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• 2002

컴퓨터 게임은 소프트웨어 분야의 새로운 고부가가치 영역으로 발전되어가고 있으나 개발공정과 방법론에 있어서는 경험중심의 개발 방법을 고수하고 있다. 따라서 본 논문에서는 기존의 개발방법을 정형화된 형태로 개선하기 위하여 컴포넌트 기반 개발방법의 적용을 위한 게임개발 프로세스의 정형화 모델을 제안하고, 재사용성의 향상에 따른 문제점과 해결방안을 제시하며, 정형화된 모델의 재사용 효율성을 위하여 컴포넌트 적용 방법을 이용한 프로세스를 정형화하는 방안을 제시하고자 한다.