篮球视频中球员的分割与跟踪算法

分割与跟踪一直是视频图像处理的一个热门问题。针对篮球视频中激烈运动的球员队属和跟踪问题,实现了一个实时的球员分割与跟踪算法。首先,不同于一般的分割方法,采用基于两个级别（像素级和帧级）实时分割和背景更新的背景减除方法,实现了对球员的分割;接着,通过将球员与模板进行马式距离比较来辨识球员队属;然后,使用基于核的目标跟踪方法,实现了在激烈比赛中对球员的准确跟踪。实验结果表明,提出的算法能够很好地辨别各个球员的队属问题并在不完全遮挡的情况下跟踪多个球员,而且在球员形态变化较大时也能稳定地跟踪。     

Influence of head-up displays’ characteristics on user experience in video games

Head-up displays (HUD) are important parts of visual interfaces of virtual environments such as video games. However, few studies have investigated their role in player–video game interactions. Two experiments were designed to investigate the influence of HUDs on player experience according to player expertise and game genre. Experiment 1 used eye-tracking and interviews to understand how and to what extent players use and experience HUDs in two types of commercial games: first-person shooter and real-time strategy games. Results showed that displaying a permanent HUD within the visual interface may improve the understanding of this environment by players. They also revealed that two HUD characteristics, namely composition and spatial organization, have particular influence on player experience. These critical characteristics were manipulated in experiment 2 to study more precisely the influence of HUD design choices on player experience. Results showed that manipulation of design of these HUD characteristics influences player experience in different ways according to player expertise and game genre. For games with HUDs that are perceived as very useful, the higher player expertise is, the more player experience is influenced. Recommendations for video game design based on these results are proposed.     

QoE assessment of fairness in networked game with olfaction: influence of time it takes for smell to reach player

In this paper, we carry out QoE (Quality of Experience) assessment of fairness between players in a networked game with olfaction. In the assessment, we investigate the influence of the time it takes for a smell to reach a player on the fairness. As the networked game, we deal with a fruit harvesting game in which two players play in a 3D virtual space, and we change the time it takes for a smell to reach a player by generating constant delays at two terminals. As a result, for example, we illustrate that the fairness is hardly damaged when the constant delays are smaller than about 500 ms.     

Multi-objective design method based on evolution game and its application for suspension

Through research and bionics of biology survival mode, game players with competition, cooperation and self-adaptation capacity are introduced in the multi-objective design. The dynamic behavior and bounded rationality in game processes for players are considered according to Chinese saying “In success, commit oneself to the welfare of the society; in distress, maintain one’s own integrity”. An evolution rule, Poor-Competition-Rich-Cooperation (short for PCRC), is proposed. Then, the corresponding payoff functions of competition and cooperation behavior are established and a multi-objective design method based on evolution game is proposed. The calculation steps are as follows: 1) Taking the design objectives as different game players, and calculating factors of the design variables to objective and fuzzy clustering. The design variables are divided into multiple strategy subsets owned by each game player. 2) According to the evolution rule, each player determines its behavior and payoff function in this game round. 3) In their own strategy subsets, each game player takes their payoff as mono-objective for optimization. It gives the best strategy upon other players. And so the best strategies of all players conform the group strategy in this round. The final equilibrium solution is obtained through multi-round game based on convergence criterion. The validity and reliability of this method are shown by the results of an example of a tri-objective optimization design of passive suspension parameters.     

RTS游戏中用户行为的神经网络预测模型

即时战略游戏(简称RTS游戏)中,用户的行为由于游戏自身庞大的决策空间而难以预测.针对这个问题,提出了通过对RTS游戏的对战记录进行分析,建立5种结构的神经网络模型来预测用户行为的方法.模型考虑了不同时间片的状态对于决策行为的影响,设计了单时间片输入和双时间片输入的神经网络,并与基于动态贝叶斯网络的模型进行了比较.实验结果表明,基于单时间片输入的神经网络模型能够更加快速地完成训练过程并达到满意的预测准确度.     

Bayesian Coalition Game for Contention-Aware Reliable Data Forwarding in Vehicular Mobile Cloud

The exponential growth in the demands of users to access various resources during mobility has led to the popularity of Vehicular Mobile Cloud. Vehicular users may access various resources on road from the cloud which acts as a service provider for them. Most of the existing proposals on vehicular cloud use unicast sender-based data forwarding, which results in an overall performance degradation with respect to the metrics such as packet delivery ratio, end-to-end delay, and reliable data transmission. Most of the applications for vehicular cloud have tight upper bounds with respect to reliable transmission. In view of the above, in this paper, we formulate the problem of reliable data forwarding as a Bayesian Coalition Game (BCG) using Learning Automata concepts. Learning Automata (LA) are assumed as the players in the game stationed on the vehicles. For taking adaptive decisions about reliable data forwarding, each player observes the moves of the other players in the game. For this purpose, a coalition game is formulated among the players of the game for taking adaptive decisions. For each action taken by a player in the game, it gets a reward or a penalty from the environment, and accordingly, it updates its action probability vector. An adaptive Learning Automata based Contention Aware Data Forwarding (LACADF) is also proposed. The proposed scheme is evaluated in different network scenarios with respect to parameters such as message overhead, throughput, and delay by varying the density and mobility of the vehicles. The results obtained show that the proposed scheme is better than the other conventional schemes with respect to the above metrics.     

P2P MMOG中基于状态差的欺骗检测机制

提出一种适合P2P MMOG的基于状态差的欺骗检测机制。采用定积分对某玩家在其他玩家游戏视图中的状态差进行量化，并在参考网络延迟的基础上根据状态差判定该玩家在游戏过程中是否进行了欺骗。判断标准为既定阈值。实验结果表明，该文提出的欺骗检测机制能有效检测出导致玩家状态不一致类型的欺骗，提高了游戏的安全性。     

Interactive strategy sets in multiple payoff games

In game theory, it is usually assumed that each player has only one payoff function and the strategy set of the game is composed of the topological product of individual players’ strategy sets. In real business and system design or control problems, however, players’ strategy sets may be interactive and each player may have more than one payoff function. This paper, investigates the more general situation of multiple payoff and multiple person games in a normal form. In this paper, each player has several payoff functions which are dominated by certain convex cones, and the feasible strategy set of each player may be interactive with those of the other players. This new model is applied to a classical example without requiring variational and quasi-variational inequalities, or point-to-set mappings.     

面向游戏体验的玩家匹配综述

玩家匹配是一种让等待游戏的玩家以开始一局在线多人游戏为目的自动地匹配到一起的技术。这些玩家希望得到有趣和平衡的游戏体验,不论是相互合作还是竞争,并且常常以团队的形式。而在线竞技游戏中玩家的满意度,因涉及到玩家间的交互而难以确保。因此,为了满足玩家的需求．研究人员将玩家匹配系统作为增强玩家游戏体验的手段。形成了一个新兴的研究领域：面向游戏体验的玩家匹配。该研究重点介绍两种玩家匹配方法：基于玩家水平的方法和基于玩家角色的方法．并对近年来出版的有关增强玩家游戏体验的玩家匹配文献进行调查和分析。     

Behavlets: a method for practical player modelling using psychology-based player traits and domain specific features

As player demographics broaden it has become important to understand variation in player types. Improved player models can help game designers create games that accommodate a range of playing styles, and may also facilitate the design of systems that detect the currently-expressed player type and adapt dynamically in real-time. Existing approaches can model players, but most focus on tracking and classifying behaviour based on simple functional metrics such as deaths, specific choices, player avatar attributes, and completion times. We describe a novel approach which seeks to leverage expert domain knowledge using a theoretical framework linking behaviour and game design patterns. The aim is to derive features of play from sequences of actions which are intrinsically informative about behaviour—which, because they are directly interpretable with respect to psychological theory of behaviour, we name ‘Behavlets’. We present the theoretical underpinning of this approach from research areas including psychology, temperament theory, player modelling, and game composition. The Behavlet creation process is described in detail; illustrated using a clone of the well-known game Pac-Man, with data gathered from 100 participants. A workshop-based evaluation study is also presented, where nine game design expert participants were briefed on the Behavlet concepts and requisite models, and then attempted to apply the method to games of the well-known first/third-person shooter genres, exemplified by ‘Gears of War’, (Microsoft). The participants found 139 Behavlet concepts mapping from behavioural preferences of the temperament types, to design patterns of the shooter genre games. We conclude that the Behavlet approach has significant promise, is complementary to existing methods and can improve theoretical validity of player models.     

Are two better than one? Playing singly,playing in dyads in a computerized simulation of the Israeli–Palestinian conflict

The study examined a computerized simulation of the Israeli–Palestinian conflict as a peace education tool for Israeli female undergraduate students of Palestinian and Jewish origin. To win the game, players are required to arrive at a two-state solution of the conflict. 100 Israeli female students of Palestinian and Jewish origin either supporting or opposing this solution played the game singly or in dyads. The rules of the study required players in dyads to reach mutual agreement on every action in the game. Results indicated that 19 out of 25 dyads resolved the conflict in the game as opposed to 16 out of 50 single players. In addition, players in dyads took more political actions and less security actions than single players did. Finally, players in dyads preferred to focus more on political actions than on security actions in the game. The abovementioned results point out three key implications for peace education. First, PeaceMaker reduces the tension and the charged atmosphere between Jewish and Palestinian players. Second, the game should be played in dyads and not singly. Finally, dyads should be comprised of a Jewish player and a Palestinian player in order to challenge their interaction and game behavior.     

Non-clairvoyant Scheduling Games

In a scheduling game, each player owns a job and chooses a machine to execute it. While the social cost is the maximal load over all machines (makespan), the cost (disutility) of each player is the completion time of its own job. In the game, players may follow selfish strategies to optimize their cost and therefore their behaviors do not necessarily lead the game to an equilibrium. Even in the case there is an equilibrium, its makespan might be much larger than the social optimum, and this inefficiency is measured by the price of anarchy—the worst ratio between the makespan of an equilibrium and the optimum. Coordination mechanisms aim to reduce the price of anarchy by designing scheduling policies that specify how jobs assigned to a same machine are to be scheduled. Typically these policies define the schedule according to the processing times as announced by the jobs. One could wonder if there are policies that do not require this knowledge, and still provide a good price of anarchy. This would make the processing times be private information and avoid the problem of truthfulness. In this paper we study these so-called non-clairvoyant policies. In particular, we study the RANDOM policy that schedules the jobs in a random order without preemption, and the EQUI policy that schedules the jobs in parallel using time-multiplexing, assigning each job an equal fraction of CPU time.     

A review of: “HUMANIZED INPUT” Tom Gilb and Gerald M. Weinberg Winthrop Computer Series,Winthrop Publishing,Cambridge, Mass. 1977 383 pages $4.00 ISBN 0-87626-345-7

Kayles is a nonpartizan two-person game. In such games the moves available to both the players are the same and either the player on move wins or the previous player wins. In the “normal form” of the game, the last player who can make a move is declared the winner. In the “misere form” of the game, the player who makes the last move is declared the loser. The complete analysis of the normal form of the game of Kayles has been described by Berlekamp, Conway, and Guy. This paper completes their analysis of the misere form of Kayles. This is done on the basis of certain properties of what have been called “wild” positions of misere games.     

Algorithms for Finding Repeated Game Equilibria

This paper describes computational techniques for finding all equilibria in infinitely repeated games with discounting and perfect monitoring. It illustrates these techniques with a three player Cournot game. This is the first infinitely repeated three player game ever solved. The paper also presents the solution for the set of equilibria in a two country tariff war. In both games the set of equilibria is large even when the players are not patient.     

Computerized real-time analysis of football games

Computer systems support many coaching activities performed before and after competitions, such as strategy development and performance evaluation, but competent assistance during games is much more demanding. It requires real-time interpretation of sensor data, the recognition and classification of ball actions, and fast-action game analysis and assessment. Only recently has high-precision microwave technology enabled computer systems to simultaneously track the position of players and the ball. Consequently, real-time game analysis systems must be able to automatically recognize intentional activities in a multiagent system with continually acting agents. To meet these demands, we've developed the football interaction and process model and a software system that can acquire, interpret, and analyze this model. Our FIPM system can acquire models of player skills, infer action-selection criteria, and determine player and team strengths and weaknesses.     

Numerical control optimization methods in one pursuit-evasion problem

This paper is devoted to the construction and study of different numerical suboptimal strategies of the pursuing player in a nonlinear three-dimensional pursuit-evasion game problem. The dynamics of the objects correspond to the known game of two cars [1]. The distinction of this problem from those considered before is the cost function structure, which contains the angular position of the velocity vectors with respect to the line of sight in addition to the distance between the players. In order to construct the numerical strategies of the pursuing player, we use the results of [2–6], where the elements of optimal control for simplified problems are obtained by using the Pontryagin maximum principle and the basic Isaacs-Bellman equation. On the basis of the strategies presented, we propose the algorithm for numerical construction of a suboptimal synthesis in the entire phase space of the initial problem. This algorithm follows an idea formulated in [7]. The numerical results of the suboptimal synthesis in a certain subdomain of the phase space are performed for some specified values of the parameters.     

A fuzzy approach to strategic games

A game is a decision-making situation with many players, each having objectives that conflict with each other. The players involved in the game usually make their decisions under conditions of risk or uncertainty. In the paper, a fuzzy approach is proposed to solve the strategic game problem in which the pure strategy set for each player is already defined. Based on the concepts of fuzzy set theory, the approach uses a multicriteria decision-making method to obtain the optimal strategy in the game, a method which shows more advantages than the classical game methods. Moreover, with this approach, some useful conclusions are reached concerning the famous “prisoner's dilemma” problem in game theory     

A Postmodern Theory of Cyberterrorism: Game Theory

ABSTRACT

This article analyzes how the battle between computer security experts and cyberterrorists can be explained through game theory. This article is important because it not only applies game theory to the study of cyberterrorism, which has been rarely done so far, but it also breaks new ground by intersecting the game theoretical model with another theory, social network theory. An important thesis of this analysis is that under the principles of game theory, each player is assumed to be rational; all players wish the outcome to be as positive or rewarding as possible. Another key argument is that game theory is a postmodern theory; against opponents who wage attacks in a postmodern fashion, conventional strategies lead nowhere. The cyberterrorist and the cyber forensics expert not only engage in real-time game play but also use tactics that are not conceivable in conventional conflict.     

A Video-Based 3D-Reconstruction of Soccer Games

In this paper we present SoccerMan, a reconstruction system designed to generate animated, virtual 3D views from two synchronous video sequences of a short part of a given soccer game. After the reconstruction process, which needs also some manual interaction, the virtual 3D scene can be examined and 'replayed' from any viewpoint. Players are modeled as so-called animated texture objects, i.e. 2D player shapes are extracted from video and texture-mapped onto rectangles in 3D space. Animated texture objects have shown very appropriate as a 3D representation of soccer players in motion, as the visual nature of the original human motion is preserved. The trajectories of the players and the ball in 3D space are reconstructed accurately. In order to create a 3D reconstruction of a given soccer scene, the following steps have to be executed: 1) Camera parameters of all frames of both sequences are computed (camera calibration). 2) The playground texture is extracted from the video sequences. 3) Trajectories of the ball and the players' heads are computed after manually specifying their image positions in a few key frames. 4) Player textures are extracted automatically from video. 5) The shapes of colliding or occluding players are separated automatically. 6) For visualization, player shapes are texture-mapped onto appropriately placed rectangles in virtual space. SoccerMan is a novel experimental sports analysis system with fairly ambitious objectives. Its design decisions, in particular to start from two synchronous video sequences and to model players by texture objects, have already proven promising.     

Coordination via genetic learning

This paper uses genetic algorithms to model the solution to a coordination problem through learning. The coordination problem arises out of the following two stage game. At core of the two stage game is a model of social interaction in which players use visible goods as signals about the identity of other players. If these signals are informative enough, players use them to condition their social interaction. Importantly, accurate signals are mutually beneficial. This game is then wrapped in another in which players choose their visible goods. There are many types of players and many visible goods that could be used to signal type. There are many equilibria of the two stage game, some of which allow individuals to perfectly signal their type in all social interactions, and others of which do not. The perfect signaling equilibria Pareto dominate the others, but since there are many of them, the players face a difficult coordination problem. We approach this coordination problem using genetic algorithms to simulate learning in this game. A player is a genetic code that evolves via selection.Questions of primary interest concern the set of parameter values such that the players manage to solve the coordination problem. The results of simulations indicate that the convergence of the genetic algorithm to a perfect signaling equilibrium depends on the values of the parameters that determine players' payoffs.We analyze two different scenarios. In one scenario, each player makes one (unconditional) decision to either use the visible goods displayed by other players as type signals, or to ignore the visible goods they display. In the other scenario, the decision to regard a player's visible good as a type signal is conditional on the good displayed. Our results indicate that it is easier for players to solve the coordination problem under the second scenario.