Altruistic behavior in a nonantagonistic positional differential game

We consider a two-person nonantagonistic positional differential game (NPDG) whose dynamics is described by an ordinary nonlinear vector differential equation. Constraints on values of players’ controls are geometric. Final time of the game is fixed. Payoff functionals of both players are terminal. The formalization of positional strategies in an NPDG is based on the formalization and results of the general theory of antagonistic positional differential games (APDGs) (see monographs by N.N. Krasovskii and A.I. Subbotin [3, 4]). Additionally, in the present paper we assume that each player, together with the usual, normal (nor), type of behavior aimed at maximizing his own functional, can use other behavior types introduced in [2, 5]. In particular, these may be altruistic (alt), aggressive (agg), and paradoxical (par) types. It is assumed that in the course of the game players can switch their behavior from one type to another. Using the possibility of such switches in a repeated bimatrix 2 × 2 game in [5, 6] allowed to obtain new solutions of this game. In the present paper, extension of this approach to NPDGs leads to a new formulation of the problem. In particular, of interest is the question of how players’ outcomes at Nash solutions are transformed. An urgent problem is minimizing the time of “abnormal” behavior while achieving a good result. The paper proposes a formalization of an NPDG with behavior types (NPDGwBT). It is assumed that in an NPDGwBT each player, simultaneously with choosing a positional strategy, chooses also his own indicator function defined on the whole game horizon and taking values in the set {normal, altruistic, aggressive, paradoxical}. The indicator function of a player shows the dynamics of changes in the behavior type demonstrated by the player. Thus, in this NPDGwBT each player controls the choice of a pair {positional strategy, indicator function}. We define the notion of a BT-solution of such a game. It is expected that using behavior types in the NPDGwBT which differ from the normal one (so-called abnormal types) in some cases may lead to more favorable outcomes for the players than in the NPDG. We consider two examples of an NPDGwBT with simple dynamics in the plane in each of which one player keeps to altruistic behavior type over some time period. It is shown that in the first example payoffs of both players increase on a BT-solution as compared to the game with the normal behavior type, and in the second example, the sum of players’ payoffs is increased.     

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.     

Consumer behavior in online game communities: A motivational factor perspective

The concept of online communities has been used to improve customers’ loyalty in recent years. While studies on transaction community such as online auction have received more attention in the literature, entertainment community such as online game has seldom been addressed. This study applies the theory of reasoned action (TRA) and modifies the technology acceptance model (TAM) to propose a research model. An empirical study involving 356 subjects was conducted to test this model. The results indicate that customer loyalty is influenced by perceived enjoyment, social norms and preference. Perceived cohesion has an indirect impact on loyalty. In addition, the finding’s practical implication suggests that community managers must overcome the problems users encounter, including suffering from an unstable system, malicious players and grief players.     

Martin's game: a lower bound for the number of sets

We investigate Martin's game (as described in Arruda et al. (Eds.), On Random R. E. Sets, Non-Classical Logics, Model Theory and Computability, North-Holland, Amsterdam, 1977, p. 283) and prove that the upper bound from the above mentioned reference for the number of sets needed to construct a winning strategy, is almost tight.     

Towards a framework for online game adoption

Drawing on Uses and Gratifications theory, this paper proposes and empirically tests an integrated model that depicts the factors that have the potential to impact the behavioral intention to adopt online games. The model is tested with data collected from 308 students in an American university. Overall, the results revealed that the effect of enjoyment was very crucial, and those of social interaction and achievement are moderate, but that of flow of experience did not influence behavioral intention. Results also indicated that visual appeal and escapism are important factors that affect and precede enjoyment.     

Designing for collaboration: a study in intergenerational social game design

This paper presents a study of a computer game designed for the elderly, allowing them to train their memory while playing the game. The game supports both a single-player and a multiplayer mode, in which the elderly can play with their friends or family using an embedded video chat application. The main question that is addressed in this paper is how the elderly gamers’ experience is influenced by the possibility to communicate directly with the other players. The study presents a comparison of the game experience and appreciation of older users and their (grand)children playing the game together, with or without the video chat application. Most importantly, the study shows that the added value of video chat is not limited to social contact, but that it also provides opportunities for the younger generation to assist the elderly during the game. In conclusion, the paper points out some intergenerational game design implications, and some future research suggestions.     

Space bounds for a game on graphs

We study a one-person game played by placing pebbles, according to certain rules, on the vertices of a directed graph. In [3] it was shown that for each graph withn vertices and maximum in-degreed, there is a pebbling strategy which requires at mostc(d) n/logn pebbles. Here we show that this bound is tight to within a constant factor. We also analyze a variety of pebbling algorithms, including one which achieves the 0(n/logn) bound.Research partially supported by DAAD (German Academic Exchange Service) Grant No. 430/402/563/5 (W.J.P.)Research partially supported by National Science Foundation grant MCS75-22870 and Office of Naval Research contract N0014-76-C-0688 (R.E.T. and J.R.C.).Reproduction in whole or in part is permitted for any purpose of the United States Government.     

Data-abstraction refinement: a game semantic approach

This paper presents a semantic framework for data abstraction and refinement for verifying safety properties of open programs with integer types. The presentation is focused on an Algol-like programming language that incorporates data abstraction in its type system. We use a fully abstract game semantics in the style of Hyland and Ong and a more intensional version of the model that tracks nondeterminism introduced by abstraction in order to detect false counterexamples. These theoretical developments are incorporated in a new model-checking tool, Mage, which implements efficiently the data-abstraction refinement procedure using symbolic and on-the-fly techniques.     

Efficient change management in long-term composed services

We present an efficient framework for managing changes in Long-term Composed Services (LCSs). Because we assume LCSs outsource their functionality from autonomous third-party Web service providers, there is a need to select the best Web service replacements when changes are induced at the LCS level. We propose a framework where managing changes in LCSs is modeled as a dual service query optimization process. In the first phase, reputation is used as a trust mechanism to weed out those Web services that do not exhibit acceptable reputation. In the second phase, the non-functional requirements represented in and by the Quality of Web Service (QoWS) are used to further narrow down the set of reputable Web services to those that also best adhere to the QoWS requirements.     

A fuzzy long-term investment planning model for a GenCo in a hybrid electricity market considering climate change impacts

We study the long-term generation capacity investment problem of an independent power generation company (GenCo) that functions in an environment where GenCos perform business with both bilateral contracts (BC) and transactions in the day-ahead market (DAM). A fuzzy mixed integer linear programming model with a fuzzy objective and fuzzy constraints is developed to incorporate the impacts of imprecision/uncertainty in the economic environment on the calculation of the optimal value of the GenCo’s objective function. In formulating the fuzzy objective function we also include the potential impacts of climate change on the energy output of hydroelectric power plants. In addition to formulating and solving the capacity planning/investment problem, we also performed scenario-based (sensitivity) analysis to explore how investment decisions of the GenCos change when fuzziness (tolerance) in the maximum energy output of hydroelectric units and/or drought expectation increases. The proposed model is novel and investigates the effects of factors like drought expectations of climate changes, hydroelectric power plant investments, and other power generation technology investment options.     

A foundation for the study of behavior change support systems

The emerging ambient persuasive technology looks very promising for many areas of personal and ubiquitous computing. Persuasive applications aim at changing human attitudes or behavior through the power of software designs. This theory-creating article suggests the concept of a behavior change support system (BCSS), whether web-based, mobile, ubiquitous, or more traditional information system to be treated as the core of research into persuasion, influence, nudge, and coercion. This article provides a foundation for studying BCSSs, in which the key constructs are the O/C matrix and the PSD model. It will (1) introduce the archetypes of behavior change via BCSSs, (2) describe the design process for building persuasive BCSSs, and (3) exemplify research into BCSSs through the domain of health interventions. Recognizing the themes put forward in this article will help leverage the full potential of computing for producing behavioral changes.     

Design for emergence: experiments with a mixed reality urban playground game

In this paper we present our work in the design of ubiquitous social experiences, aiming to foster group participation and spontaneous playful behaviours in a city environment. We outline our approach of design for emergence: to provide just enough of a game context and challenge for people to be creative, to extend and enrich the experience of play through their interaction in the real world. CitiTag is our mixed reality testbed, a wireless location-based multiplayer game based on the concept of playground ‘tag’. We describe the design and implementation of CitiTag and discuss results from two user studies.     

Sentiment analysis and Twitter: a game proposal

Pervasive sensing of people’s opinions is becoming critical in strategic decision processes, as it may be helpful in identifying problems and strengthening strategies. A recent research trend is to understand users’ opinions through a sentiment analysis of contents published in the Twitter platform. This approach involves two challenges: the large volume of available data and the large variety of used languages combined with the brevity of texts. The former makes manual analysis unreasonable, whereas the latter complicates any type of automatic analysis. Since sentiment analysis is a difficult process for computers, but it is quite simple for humans, in this article, we transform the sentiment analysis process into a game. Indeed, we consider the game with a purpose approach and we propose a game that involves users in classifying the polarity (e.g., positive, negative, neutral) and the sentiment (e.g., joy, surprise, sadness) of tweets. To evaluate the proposal, we used a dataset of 52,877 tweets, we developed a Web-based game, we invited people to play the game, and we validated the results through two different methods: ground-truth and manual assessment. The obtained results showed that the game approach is effective in measuring people’ sentiments and also highlighted that participants liked to play the game.     

Feedback Stackelberg strategy for a two player game

Using dynamic programming, feedback Stackelberg strategies are derived for the general linear quadratic discrete-time game.     

3D sound spatialization with game engines: the virtual acoustics performance of a game engine and a middleware for interactive audio design

Virtual Reality - This study analyses one of the most popular game engines and an audio middleware to reproduce sound according to sound propagation physics. The analysis focuses on the...