• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.3
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• pp.1336-1356
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• 2017

The spectrum scarcity crisis has resulted in a shortage of resources for many emerging wireless services, and research on dynamic spectrum management has been used to solve this problem. Game theory can allocate resources to users in an economic way through market competition. In this paper, we propose a bidding game-based spectrum allocation mechanism in cognitive radio network. In our framework, primary networks provide heterogeneous wireless service and different numbers of channels, while secondary users have diverse bandwidth demands for transmission. Considering the features of traffic and QoS demands, we design a weighted interference graph-based grouping algorithm to divide users into several groups and construct the non-interference user-set in the first step. In the second step, we propose the dynamic bidding game-based spectrum allocation strategy; we analyze both buyer's and seller's revenue and determine the best allocation strategy. We also prove that our mechanism can achieve balanced pricing schema in competition. Theoretical and simulation results show that our strategy provides a feasible solution to improve spectrum utilization, can maximize overall utility and guarantee users' individual rationality.

• Journal of Korea Game Society
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• v.19 no.6
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• pp.37-48
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• 2019

This paper aims to clarify the game performance and its principle and operation method at the depth of successful content through gameness transition, which is one of the transmedia phenomena of games. This paper investigated the current state of gameness transition and analyzed the game structure and working principle by using Chris Crawford's creative expression taxonomy model. As a result, the types of gameness transition could be extracted into space exploration type, stage type, reasoning competition type, and mutual competition type.

• Journal of Korea Game Society
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• v.21 no.1
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• pp.55-66
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• 2021

Multi-thread programming is essential in high performance game programming. But, the widely used C++11 shared_ptr and weak_ptr have malfunction and performance problems in multi-thread environments. In this paper, we propose Lock-Free shared_ptr and weak_ptr, which have higher performance than current error preventing methods. These use a non-blocking algorithm to prevent data race in multi-thread environments. As a result of experimenting in an 8 thread environment, performance has improved up to 7424% in a situation where competition between threads is low, and 3767% in high competition.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.11
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• pp.668-674
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• 2003

The electric marketplace is in the midst of major changes designed to promote competition. No longer vertically integrated with guaranteed customers and suppliers, electric generators and distributors will have to compete to sell and buy electricity. Unit commitment (UC) in such a competitive environment is not the same as the traditional one anymore. The objective of UC is not to minimize production cost as before but to find the solution that produces a maximum profit for a generation firm. This paper presents a hi-level formulation that decomposes the UC game into a generation-decision game (first level game) and a state(on/off)-decision game (second level game). Derivation that the first-level game has a pure Cournot Nash equilibrium(NE) helps to solve the second-level game. In case of having a mixed NE in the second-level game, this paper chooses a pure strategy having maximum probability in the mixed strategy in order to obviate the probabilistic on/off state which may be infeasible. Simulation results shows that proposed method gives the adequate UC solutions corresponding to a NE.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.12
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• pp.2143-2149
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• 2010

Market price and curtailment amounts of the Demand Resource Market(DRM) are determined by competition between electricity consumers. An important aspect of the DRM involves the assessment of strategic behavior of participants for maximizing their profits. This paper presents economic equilibrium models for simulating imperfect competition among electricity consumers in the DRM and analyzes the models at Nash Equilibrium of Game Theory. The proposed demand functions and supply functions of DRM are based on the Demand Resource Market Rules in Korean electricity market. Simulation results show that the models are adequate for obtaining Nash Equilibrium of consumers' competitive curtailment.

• Journal of the HCI Society of Korea
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• v.13 no.3
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• pp.5-15
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• 2018

The biggest characteristic of Social Network Game(SNG) is that games are played through competition and cooperation with the actual acquaintances based on SNS. Even though such competition and challenge spirit have been dealt importantly as preceding factors having influence on the flow in games in the existing game area, it is rare to find researches deeply considering the characteristics of ranking competition between acquaintances in SNG. Moreover, it was not considered that such acquaintances could be the targets of competition and also challenge at the same time in SNG. Therefore, this study examined the achievements(big differences in ranking, small differences in ranking) of the targets for comparison and closeness(strong ties, weak ties) with the targets for comparison as factors having influence on competition and challenge spirit, and also empirically analyzed the influence of such factors and interactions between factors on players' competition and challenge spirit in the ranking competitive society, by analyzing the characteristics of ranking competition between acquaintances in the mobile puzzle, SNG based on SNS through the analysis on the preceding research on the self-evaluation maintenance model of the social comparison theory. In the results, when preferentially exposing competitors with small difference in ranking and also exposing competitors with stronger ties, players' competition is stimulated, so that it can improve their challenge spirit. Such results of this study can be expected to a lot contribute to the actual design work of SNG ranking table contents.

• International Journal of Contents
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• v.7 no.4
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• pp.10-18
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• 2011

Cooperative Group Games (CGG) emphasize participation, challenges and fun by cooperation among group members rather than competition. CGGs have been proven to be an efficient education method that teaches the value of cultivating cooperation skills, discipline, and sense of public order for tackling problems together through various types of interactions. When integrated with computer game technology, the general classic CGG can be reborn with new educational and entertaining aspects. To combine the joy of physical movement of group games and the richness of computer game contents, a motion based arcade CGG has been developed in this study, based on the original ideas and structures of classic off-line CGGs. While implementing the classic game concepts in arcade environment, various design attributes have been considered and applied, which were supposed to promote cooperative game play. Overall, the process of the implementation and test results of our four CGGs suggest several design strategies for effective arcade CGGs.

• Journal of Korea Multimedia Society
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• v.24 no.4
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• pp.593-600
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• 2021

In this paper, we present the FlappyBird Competition System (FCS) implementation, a competition-based automated assessment system used in an entry-level artificial intelligence (AI) course at a university. The proposed system provides an evaluation method suitable for AI courses while taking advantage of automated assessment methods. Students are to design a neural network structure, train the weights, and tune hyperparameters using the given reinforcement learning code to improve the overall performance of game AI. Students participate using the resulting trained model during the competition, and the system automatically calculates the final score based on the ranking. The user evaluation conducted after the semester ends shows that our competition-based automated assessment system promotes active participation and inspires students to be interested and motivated to learn AI. Using FCS, the instructor significantly reduces the amount of time required for assessment.

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.145-151
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• 2011

This study assumed the competitive structure based on genre classification for Korean online game contents market, and carried out the analysis on the degree and characteristics of the competition that appear differently in each sub market classified according to the genre. First, to analyze the market power of the rank 1 and 2 game contents in each genre, using the play time share ratio and standard deviation statistics values in the genre, ANOVA analysis and Cluster analysis were carried out for each genre. According to ANOVA analysis result, in the rank 1 game share ratio in each genre, there was a relationship of 'FPS/Racing > RST/Sports > Poker > Go-stop > RPG > Arcade > Board', and in the play time total share ratio of rank 1 and 2 games, the relationship of 'RTS > FPS/Racing > Sports > RPG > Go-stop > Poker > Arcade > Board' was verified. And in Cluster analysis, the groups of the genres with the degree of market power tendency and the variability at similar level were classified and stated.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.3
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• pp.47-55
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• 2016

The proliferation of the Internet and related technologies has led to a new form of distribution channels, namely online retailers. The conventional offline and the new online retailers have different transaction costs perceived by the consumers in the following perspectives: the accessibility to the product information, the traffic cost and the opportunity cost for the time to visit the store, the delivery time and the possibility of 'touch and feel' to test the quality of the product. In particular, the online retailers have lower distribution cost structure in that they do not have physical stores, which results in lower selling price. Thus they continuously offer price competition against offline retailers using the lower selling cost as competitive weapon. Moreover the emergence of the social commerce is likely to intensify the competition between the online and offline retailers. To survive in this fierce competition, the offline retailers are trying to defend their business interests by sticking to offline transaction in anticipation of increased customer loyalty, customer's preference for 'touch and feel' style shopping, and others. Despite of these efforts, customers who touch and feel a product in an offline store but purchase the product through an online retailer are increasing. To protect such customers, recently, some of the offline retailers began to provide the mobile discount service (MDS) which enables the offline customers to purchase a product at a discounted price through the mobile applications. In business competitions, the price discount strategy is usually considered to secure more market share at the cost of lower profit. In this study, however, we analyze the effect of MDS as a weapon for securing more profit. To do this, we set up a game model between the online and offline retailers which incorporates the effect of the MDS. By numerically analyzing the Nash equilibrium of the game, some managerial implications for using the MDS for more profit are discussed.