On Weakly Cancellative Fuzzy Logics

Starting from a decomposition result of monoidal t-norm-basedlogic (MTL)-chains as ordinal sums, we focus our attention ona particular kind of indecomposable semihoops, namely weaklycancellative semihoops. The weak cancellation property is provedto be the difference between cancellation and pseudocomplementation,so it gives a new axiomatization of product logic and MTL. Byadding this property, some new fuzzy logics (propositional andfirst-order) are defined and studied obtaining some resultsabout their (finite) strong standard completeness and otherlogical and algebraic properties.     

针对有向无环图结构的多版本分布模式优化

为提高多版本协同设计的整体存储及查询性能,针对具有有向无环图结构、结合完整和增量存储的多版本模型,在研究多版本演化过程、版本间继承关系的基础上,提出可双向恢复的增量版本定义方式,将有向无环图结构转换成带权无向图结构。以版本差异为指标计算版本恢复成本,使用改进的Floyd算法,以计算所有版本最小恢复成本为目标设计多版本分布模式优化算法。分析和实例结果验证,该方法可以提高协同设计多版本的数据存储可靠性和提取效率,并且优化算法具有较高的计算效率。     

On Symbolic Verification of Weakly Extended PAD

We consider the verification problem of a class of infinite-state systems called wPAD. These systems can be used to model programs with (possibly recursive) procedure calls and dynamic creation of parallel processes. They correspond to PAD models extended with an acyclic finite-state control unit, where PAD models can be seen as combinations of prefix rewrite systems (pushdown systems) with context-free multiset rewrite systems (synchronization-free Petri nets). Recently, we have presented symbolic reachability techniques for the class of PAD based on the use of a class of unranked tree automata. In this paper, we generalize our previous work to the class wPAD which is strictly larger than PAD. This generalization brings a positive answer to an open question on decidability of the model checking problem for wPAD against EF logic. Moreover, we show how symbolic reachability analysis of wPAD can be used in (under) approximate analysis of Synchronized PAD, a (Turing) powerful model for multithreaded programs (with unrestricted synchronization between parallel processes). This leads to a pragmatic approach for detecting the presence of erroneous behaviors in these models based on the bounded reachability paradigm where the notion of bound considered here is the number of synchronization actions.     

中国民间游戏和电子游戏的社会功能差异

游戏是一种古老的社会文化现象,自从有了人类就有了游戏。随着人类社会的发展、经济和科技水平的不断上升,游戏的概念和内涵也不再是跳皮筋、踢毽子等民间游戏活动。一种承载着更多经济、科技和文化内涵的游戏行为——电子游戏正在渗透到人们的生活中,人们认识到它更多的社会功能和价值,这种社会功能和价值因为游戏的内容、形式以及物质载体的巨大变化而形成了民间游戏和电子游戏的很大差异。     

弱持续Petri网的行为与结构性质

弱持续Petri网是Petri网的一个子类,与系统的持续性密切相关.本文刻画了活的弱持续Petri网的一个行为特征,即,如果在一个标识M下两个不同的变迁t1与t2均是使能的,则存在两个变迁序列σ’与σ″满足:(1)t1σ’t2与t2σ″t1在M下是使能的,(2)t1不出现在σ″中,(3)t2不出现在σ’,并且(4)σ’与σ″的发生数向量相同.同时,本文揭示了弱持续网的两个结构特征,并证明了持续Petri网的同步合成网仍然保持持续性.这些结论丰富了Petri网的基本理论.     

On Weakly Smooth Uninorms on Finite Chain

In this paper, we characterize all weakly smooth uninorms (i.e., uninorms with smooth underlying operators) defined on a finite chain. It is proved that any such uninorm is determined by three unary functions and vice versa. As a by‐product, we obtain the characterizations of smooth t‐norms, smooth t‐conorms through additive generators and show that on a finite chain, there exists no counterpart of the class of uninorms continuous in ]0, 1[².     

关于定量与定性微分对策

本文将文献[2,3,4,5,7]中的方法加以发展,用来解决一类定量和定性微分对策问题.对于定量对策,我们推出最优策略(u,v)所应满足的必要条件,即"双方极值原理".对于定性对策,也得到最优策略(u,v)的必要条件、且不必如文献[1]中那样限于"小范围".并确定了组成界栅(barrier)的轨线的方程. 还讨论了一些其他问题,如充分条件、目标集的更一般的形式、定性对策与能控性问题间的关系等. 可见,这种方法是一种可用来解决多种类型的最优控制和微分对策问题的有力工具. 文中附有二例.     

基于有向无环图的成本-时间优化调度算法

网格计算环境下,基于有向无环图(DAG)的成本-时间优化调度算法运用经济规律把网格用户的任务映射到网格资源中运行.OGS算法考虑了任务间的优先关系,使得任务完成时间最小,但没考虑到在网格环境中所需的成本.Nimrod/G模型中提出基于时间和成本限制下的优化调度算法(DBC)考虑了时间和成本,但没考虑任务问的优先关系.本文综合考虑了成本-时间因素以及任务间的优先关系,在不增加完成时间的基础上,把任务映射到价格便宜的机器上,提出了基于有向无环图的成本-时间优化调度算法.通过仿真表明,相对OGS算法,该算法减少了所需成本.     

On the Convergence of Multicast Games in Directed Networks

We investigate the convergence of the price of anarchy after a limited number of moves in the classical multicast communication game when the underlying communication network is directed. Namely, a subset of nodes of the network are interested in receiving the transmission from a given source node and can share the cost of the used links according to fixed cost sharing methods. At each step, a single receiver is allowed to modify its communication strategy, that is to select a communication path from the source, and assuming a selfish or rational behavior, it will make a best response move, that is it will select a solution yielding the minimum possible payment or shared cost. We determine lower and upper bounds on the price of anarchy, that is the highest possible ratio among the overall cost of the links used by the receivers and the minimum possible cost realizing the required communications, after a limited number of moves under the fundamental Shapley cost sharing method. In particular, assuming that the initial set of connecting paths can be arbitrary, we show an $O(r\sqrt{r})We investigate the convergence of the price of anarchy after a limited number of moves in the classical multicast communication game when the underlying communication network is directed. Namely, a subset of nodes of the network are interested in receiving the transmission from a given source node and can share the cost of the used links according to fixed cost sharing methods. At each step, a single receiver is allowed to modify its communication strategy, that is to select a communication path from the source, and assuming a selfish or rational behavior, it will make a best response move, that is it will select a solution yielding the minimum possible payment or shared cost. We determine lower and upper bounds on the price of anarchy, that is the highest possible ratio among the overall cost of the links used by the receivers and the minimum possible cost realizing the required communications, after a limited number of moves under the fundamental Shapley cost sharing method. In particular, assuming that the initial set of connecting paths can be arbitrary, we show an O(r?r)O(r\sqrt{r}) upper bound on the price of anarchy after 2 rounds, during each of which all the receivers move exactly once, and a matching lower bound, that we also extend to W(r^k?{r})\Omega(r\sqrt[k]{r}) for any number k≥2 rounds, where r is the number of receivers. Similarly, exactly matching upper and lower bounds equal to r are determined for any number of rounds when starting from the empty state in which no path has been selected. Analogous results are obtained also with respect to other three natural cost sharing methods considered in the literature, that is the egalitarian, path-proportional and egalitarian-path proportional ones. Most results are also extended to the undirected case in which the communication links are bidirectional.     

On Some Strongly and Weakly Homogeneous Binary Search Systems

Abstract

Given a non-empty set S and a system F of functions defined on S, the object of search is to detect an unknown element x in S, by observing the values of a sequence of test-functions f in F at x till there is enough information to detect x. The basic concepts and definitions of search theory were developed by Rényi [16, 17]. He defined various types of homogeneities for the system F and discussed the duration of the process of random search.

Strongly homogeneous systems of order two in two symbols are found to be closely related to the incidence matrix of equireplicated pairwise balanced designs. Some new systems of this type have been constructed here by using the incidence of subsets of points and m-flats of finite geometries. Properties of weakly homogeneous binary systems of order two have been studied, and some new systems constructed using association matrices and Hadamard matrices. Two series of search systems possessing an optimality property have been also constructed.     

Narrative Structure and Player Experience in Role-Playing Games

This article reports an experimental study that investigated the effects of narrative structure and number of salient decision points in a role-playing game (RPG). Previous research has proposed various theories and frameworks and posited that a branching structure with increased complexity (i.e., more salient decision points) will improve player’s enjoyment. However, no empirical study has been conducted to validate these statements. This research attempts to fill in this gap. Two hypotheses were developed based on prior research. In a controlled experiment, participants were asked to view prerecorded game play sessions based on which participant experiences were assessed. The experiment suggests that both narrative structure and number of salient decision points impact on game play experience of RPGs.     

On One Feature of Multicriteria Differential Games

Differential two-person zero-sum games with a vector payoff function are considered. A counterexample states that a payoff function component convolution into a linear convolution and further finding saddle point results in the interior instability of a set of such solutions. It is found that such saddle points are Geoffrion saddle points for an initial multicriteria game.     

浅谈电脑游戏与娱乐教育

当电脑游戏问世的时候,人们可能意识不到它所带来的社会影响。随着上个实际最后10年互联网迅速的发展,网络游戏也随之风靡全球。这带来了种种问题,广大教育工作者必须正视这些问题。而近几年来,娱乐教育的提出和发展,使教育工作者们的目光又聚焦到电脑游戏之上。电脑游戏的娱乐性如果能和教育应用结合起来,将极大地激发学习者的学习兴趣,提高学习效率和效果。电脑游戏这把双刃剑如果能被我们所掌握,将能改变其电子海洛英的恶名,而成为新的教学手段。     

On Equilibria for ADM Minimization Games

In the ADM minimization problem the input is a set of arcs along a directed ring. The input arcs need to be partitioned into non-overlapping chains and cycles so as to minimize the total number of endpoints, where a k-arc cycle contributes k endpoints and a k-arc chain contains k+1 endpoints. We study ADM minimization problem both as non-cooperative and cooperative games. In these games each arc corresponds to a player, and the players share the cost of the ADM switches. We consider two cost allocation models, a model which was considered by Flammini et al., and a new cost allocation model, which is inspired by congestion games. We compare the price of anarchy and price of stability in the two cost allocation models, as well as the strong price of anarchy and the strong price of stability.     

On the Computation of Stability in Multiple Coalition Formation Games

In non-cooperative models of coalition formation, players have to decide whether or not to participate in a coalition (alliance). Game theoretic analyses of the formation of alliances in games with externalities, stress the difficulties in designing self-enforcing treaties because of free-riding. The presence of a strong free-rider incentive prevents most alliances of being stable and/or effective. This paper focuses on computing stability in a game on multiple coalition formation with membership rules and different transfer schemes. A new mathematical programming notation for game theory concepts is outlined. To compute stability, the new notation is used for implementation into computer coding. Implementation and computation aspects are discussed. Numerical illustration of the algorithm shows that stability varies with the applied membership rules and transfer schemes. An application of coalition formation to International Environmental Agreements (lEAs) is provided.Elena Sáiz was supported by the Wageningen Institute for Environment Climate Research (WIMEK)     

Acyclic colorings of subcubic graphs

It is known that the acyclic chromatic number of a subcubic graph is at most four, and its acyclic edge chromatic number is at most five. We present algorithms that prove these two facts. Let n be the number of vertices of a graph. Our first algorithm takes O(n) time and uses four colors to properly color the vertices of any subcubic graph so that there is no 2-colored cycle. Our second algorithm takes O(n) time and uses five colors to properly color the edges of any subcubic graph so that there is no 2-colored cycle. Both are the first linear-time algorithms for the problems they solve.     

冬奥冰壶六足机器人研究

冰壶六足机器人是北京2022年冬奥会组委会需求的唯一进入冬奥会赛场的机器人。开发该机器人的目的是借助北京冬奥会展示我国机器人的自主创新能力和水平。我们重视独特设计创意,通过模仿冰壶运动员投掷冰壶的“行为特征”来设计和开发冰壶六足机器人。冰壶六足机器人设计面临多项挑战,要解决模仿人投掷冰壶行为的六足机器人的构形综合、投掷冰壶任务链与机器人行为链关联特征建立、机器人击打冰壶行为规划等问题。研制的冰壶六足机器人在北京2022年冬奥会冰立方冰壶赛场上顺利完成击打冰壶表演。     

基于有向无环图的成本-时间优化调度算法

网格计算环境下,基于有向无环图（DAG）的成本-时间优化调度算法运用经济规律把网格用户的任务映射到网格资源中运行。OGS算法考虑了任务间的优先关系,使得任务完成时间最小,但没考虑到在网格环境中所需的成本。Nimrod/G模型中提出基于时间和成本限制下的优化调度算法（DBC）考虑了时间和成本,但没考虑任务间的优先关系。本文综合考虑了成本-时间因素以及任务间的优先关系,在不增加完成时间的基础上,把任务映射到价格便宜的机器上,提出了基于有向无环图的成本-时间优化调度算法。通过仿真表明,相对OGS算法,该算法减少了所需成本。