谈产品创制活动中欲与技的关联

随着科学技术的发展和生活水平的提高,无论在物质还是在思想观念上,人们都在追求产品创制,借助企业,共同显现出自身的欲望。本文着重从设计创制活动中欲望与技术的关联的角度进行探讨,同时尝试解决设计创制活动存在的问题探索一条新路。     

用于辩证分析的多方对话协议

在基于辩论的多agent系统研究中,agent之间的对话博弈一般是双方的,然而现实中的辩论却常常涉及到多方参与者,如何实现多agent系统的多方对话博弈是当前的研究热点之一。用于多方论据博弈的辩证分析模型(DAM-MAG)是一种借鉴中国武术擂台比武思想,将多方对话博弈转化为若干个双方对话博弈的理论模型。DAM-MAG的难点在于多方对话博弈协议的设计和实现。为此,基于该理论模型提出了一种多方对话博弈协议。该协议提供了通过双方对话博弈来解决多方对话博弈问题的方法,为解决多agent系统的多方对话博弈提供了新的途径。     

Decision making in dynamic stochastic Cournot games

In this paper, the Cournot competition is modeled as a stochastic dynamic game. In the proposed model, a stochastic market price function and stochastic dynamic decision functions of the rivals are considered. Since the optimal decision of a player needs the estimation of the unknown parameters of the market and rivals’ decisions, a combined estimation-optimization algorithm for decision making is proposed. The history of the rivals’ output quantities (supplies) and the market clearing price (MCP) are the only available information to the players. The convergence of the algorithm (for both estimation and decision making processes) is discussed. In addition, the stability conditions of the equilibrium points are analyzed using the converse Lyapunov theorem. Through the case studies, which are performed based on the California Independent System Operator (CA-ISO) historical public data, the theoretical results and the applicability of the proposed method are verified. Moreover, a comparative study among the agents using the proposed method, naïve expectation and adaptive expectation in the market is performed to show the effectiveness and applicability of the proposed method.     

Cognitive-bias toward gaming-related words and disinhibition in World of Warcraft gamers

This study investigated cognitive biases toward gaming-related words and differences in cognitive performance among twelve World of Warcraft players (WWP) and thirty non-players (NP). We measured response to valenced common English and WoW jargon words using a computer-based go/no-go task. Sometimes positive valence words were the targets for the ‘go’ response, with negative-valence words as the distracters, sometimes the reverse. Target discrimination (d′) and response disinhibition (C) were calculated using a signal detection analysis. Based on questionnaire responses, there were no differences between groups in depression, anxiety, smoking or drinking, but WWP reported significantly more screen and gaming time (17.31 h/week versus 4.12 among NP). WWP had faster reaction time (RT) and better discrimination of targets from distracters (high d′) but also showed higher disinhibition (low C). WWP also showed cognitive-bias toward game-related words in the form of higher d′ for WoW jargon than common English and more disinhibition to positive-valence WoW jargon. Similar to past studies which have found alcoholics to have cognitive biases toward alcohol-related words, WWP who play frequently showed cognitive biases toward words related to the World of Warcraft game.     

Design guidelines for Classroom Multiplayer Presential Games (CMPG)

In a Classroom Multiplayer Presential Game (CMPG) peers interact collaboratively with the virtual world and amongst themselves in a shared space. The design of this kind of game, however, is a complex process that must consider instruction strategies, methodology, usability and ludic aspects. This article’s aim is to develop and systematize guidelines for the design of CMPGs. To develop these guidelines we used a three-step process: evaluating an initial implementation of a CMPG and finding its problems; defining guidelines that can help overcome these problems; and redesigning the game based on the guidelines before testing it in a real class scenario to assess how helpful the guidelines were in solving the initial problems.     

Cognitive consequences of making computer-based learning activities more game-like

Some students (base group) played the Circuit Game, a 10-level computer-based learning activity intended to help students learn how electrical circuits work. Other students (competition group) played the same game but with competition features added - including a score bar showing performance on each level, the opportunity to earn one ticket per level if a performance criterion is met, and the opportunity to win a prize based on the number of tickets earned. On a retention test given after the game, the competition group remembered significantly more than the base group (d = 0.47). On an embedded transfer test constituting the final level of the game, the groups did not differ significantly. However, on the transfer test there was a significant gender by group interaction in which men performed worse in the competition group than the base group (d = −0.54) and women performed better in the competition group than the base group (d = 0.24). Overall, adding game-like features to a computer-based learning activity caused students to pay attention to game details but did not motivate students - particularly men - to learn more deeply.     

Exploring the value of purchasing online game items

The aims of this paper are to: (1) modify the theory of consumption values in order to investigate online game users’ perceived value of purchasable game items, and (2) develop a new construct – the “integrated value of purchasing game items” – based on the modified theory of consumption values. We found that the enjoyment, character competency, visual authority, and monetary values are appropriate for describing how online game users perceive the value of game items. Utilizing second order analysis, the “integrated value of purchasing game items” was developed. To show the validity of the new construct, we developed a research model and tested it using the results of 327 valid questionnaires. Results revealed that the new construct is statistically significant in affecting users’ intention to purchase game items.     

Stackelberg Strategies for Selfish Routing in General Multicommodity Networks

A natural generalization of the selfish routing setting arises when some of the users obey a central coordinating authority, while the rest act selfishly. Such behavior can be modeled by dividing the users into an α fraction that are routed according to the central coordinator’s routing strategy (Stackelberg strategy), and the remaining 1−α that determine their strategy selfishly, given the routing of the coordinated users. One seeks to quantify the resulting price of anarchy, i.e., the ratio of the cost of the worst traffic equilibrium to the system optimum, as a function of α. It is well-known that for α=0 and linear latency functions the price of anarchy is at most 4/3 (J. ACM 49, 236–259, 2002). If α tends to 1, the price of anarchy should also tend to 1 for any reasonable algorithm used by the coordinator. We analyze two such algorithms for Stackelberg routing, LLF and SCALE. For general topology networks, multicommodity users, and linear latency functions, we show a price of anarchy bound for SCALE which decreases from 4/3 to 1 as α increases from 0 to 1, and depends only on α. Up to this work, such a tradeoff was known only for the case of two nodes connected with parallel links (SIAM J. Comput. 33, 332–350, 2004), while for general networks it was not clear whether such a result could be achieved, even in the single-commodity case. We show a weaker bound for LLF and also some extensions to general latency functions. The existence of a central coordinator is a rather strong requirement for a network. We show that we can do away with such a coordinator, as long as we are allowed to impose taxes (tolls) on the edges in order to steer the selfish users towards an improved system cost. As long as there is at least a fraction α of users that pay their taxes, we show the existence of taxes that lead to the simulation of SCALE by the tax-payers. The extension of the results mentioned above quantifies the improvement on the system cost as the number of tax-evaders decreases. Research of G. Karakostas supported by an NSERC Discovery Grant and MITACS. Research of S. Kolliopoulos partially supported by the University of Athens under the project Kapodistrias.     

Non-Cooperative Tree Creation

In this paper we consider the connection game, a simple network design game with independent selfish agents that was introduced by Anshelevich et al. (Proc. 35th Ann. ACM Symp. Theo. Comp. (STOC), pp. 511–520, 2003). Our study concerns an important subclass of tree games, in which every feasible network is guaranteed to be connected. It generalizes the class of single-source games considered by Anshelevich et al. We focus on the existence, quality, and computability of pure-strategy exact and approximate Nash equilibria. For tree connection games, in which every player holds two terminals, we show that there is a Nash equilibrium as cheap as the optimum network. In contrast, for single-source games, in which every player has at most three terminals, the price of stability is at least k−2, and it is -complete to decide the existence of a Nash equilibrium. Hence, we propose polynomial time algorithms for computing approximate Nash equilibria, which provide relaxed stability and cost efficiency guarantees. For the case of two terminals per player, there is an algorithm to find a (2+ε,1.55)-approximate Nash equilibrium. It can be generalized to an algorithm to find a (3.1+ε,1.55)-approximate Nash equilibrium for general tree connection games. This improves the guarantee of the only previous algorithm for the problem, which returns a (4.65+ε,1.55)-approximate Nash equilibrium. Tightness results for the analysis of all algorithms are derived. Our algorithms use a novel iteration technique for trees that might be of independent interest. This work has appeared in part as an extended abstract at the 31st Symposium on Mathematical Foundations of Computer Science (MFCS 2006) and the 17th International Symposium on Algorithms and Computation (ISAAC 2006). Supported by DFG Research Training Group 1042 “Explorative Analysis and Visualization of Large Information Spaces”.