WorldWideScience

Sample records for heterogeneous agents cooperation

  1. Understanding Heterogeneous Preferences of Cooperative Members

    NARCIS (Netherlands)

    Kalogeras, N.; Pennings, J.M.E.; Lans, van der I.A.; Garcia, P.; Dijk, van G.

    2009-01-01

    We study the heterogeneity in the preference structure of cooperative members. Using conjoint analysis the utility that members attach to intra-organizational and strategic attributes of their cooperative is elicited. Recognizing that members are not homogenous, a concomitant finitemixture

  2. Macroeconomic Policies and Agent Heterogeneity

    OpenAIRE

    GOTTLIEB, Charles

    2012-01-01

    Defence date: 24 February 2012 Examining Board: Giancarlo Corsetti, Arpad Abraham, Juan Carlos Conesa, Jonathan Heathcote. This thesis contributes to the understanding of macroeconomic policies’ impact on the distribution of wealth. It belongs to the strand of literature that departs from the representative agent assumption and perceives agent heterogeneity and the induced disparities in wealth accumulation, as an important dimension of economic policy-making. Within such economic envir...

  3. Heterogeneous Multi-Robot Cooperation

    Science.gov (United States)

    1994-02-01

    express my heartfelt thanks to my thesis advisor . Rod Brooks. who supported and encouraged me throughout my time at MIT. He provided a good mixture of...group than is possible with individual robots alone. 25 26 CHAPTER 3. ALLIANCE: THE COOPERATIVE ROBO ,ARCHITECTURE’ discuss the implications of these...available, robot teams should take advantage of it; however, I do not want the team to experience total breakdown when communication becomes unavailable

  4. Cooperative and Heterogeneous Indoor Localization - Experiments

    DEFF Research Database (Denmark)

    Benoît, Denis; Raulefs, Ronald; Fleury, Bernard Henri

    2013-01-01

    In this paper we present the results of real-life localization experiments performed in an unprecedented cooperative and heterogeneous wireless context. These measurements are based on ZigBee and orthogonal frequency division multiplexing (OFDM) devices, respectively endowed with received signal...

  5. Cooperative networking in a heterogeneous wireless medium

    CERN Document Server

    Ismail, Muhammad

    2013-01-01

    This brief focuses on radio resource allocation in a heterogeneous wireless medium. It presents radio resource allocation algorithms with decentralized implementation, which support both single-network and multi-homing services. The brief provides a set of cooperative networking algorithms, which rely on the concepts of short-term call traffic load prediction, network cooperation, convex optimization, and decomposition theory. In the proposed solutions, mobile terminals play an active role in the resource allocation operation, instead of their traditional role as passive service recipients in the networking environment.

  6. Cooperative heuristic multi-agent planning

    NARCIS (Netherlands)

    De Weerdt, M.M.; Tonino, J.F.M.; Witteveen, C.

    2001-01-01

    In this paper we will use the framework to study cooperative heuristic multi-agent planning. During the construction of their plans, the agents use a heuristic function inspired by the FF planner (l3l). At any time in the process of planning the agents may exchange available resources, or they may

  7. Agent control of cooperating satellites

    OpenAIRE

    Lincoln, N.K.; Veres, S.M.; Dennis, Louise; Fisher, Michael; Lisitsa, Alexei

    2011-01-01

    A novel, hybrid, agent architecture for (small)swarms of satellites has been developed. The software architecture for each satellite comprises ahigh-level rational agent linked to a low-level control system. The rational agent forms dynamicgoals, decides how to tackle them and passes theactual implementation of these plans to the control layer. The rational agent also has access to aMatLabmodel of the satellite dynamics, thus allowing it to carry out selective hypothetical reasoningabout pote...

  8. Smart Agents and Sentiment in the Heterogeneous Agent Model

    Czech Academy of Sciences Publication Activity Database

    Vácha, Lukáš; Baruník, Jozef; Vošvrda, Miloslav

    2009-01-01

    Roč. 18, č. 3 (2009), s. 209-219 ISSN 1210-0455 R&D Projects: GA MŠk(CZ) LC06075; GA ČR GP402/08/P207; GA ČR(CZ) GA402/09/0965 Institutional research plan: CEZ:AV0Z10750506 Keywords : heterogeneous agent model * market structure * smart traders * Hurst exponent Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2009/E/vacha- smart agent s and sentiment in the heterogeneous agent model.pdf

  9. Prospect Theory in the Heterogeneous Agent Model

    Czech Academy of Sciences Publication Activity Database

    Polach, J.; Kukačka, Jiří

    (2018) ISSN 1860-711X R&D Projects: GA ČR(CZ) GBP402/12/G097 Institutional support: RVO:67985556 Keywords : Heterogeneous Agent Model * Prospect Theory * Behavioral finance * Stylized facts Subject RIV: AH - Economic s OBOR OECD: Finance Impact factor: 0.931, year: 2016 http://library.utia.cas.cz/separaty/2018/E/kukacka-0488438.pdf

  10. Implications of molecular heterogeneity for the cooperativity of biological macromolecules.

    Science.gov (United States)

    Solomatin, Sergey V; Greenfeld, Max; Herschlag, Daniel

    2011-06-01

    Cooperativity, a universal property of biological macromolecules, is typically characterized by a Hill slope, which can provide fundamental information about binding sites and interactions. We demonstrate, through simulations and single-molecule FRET (smFRET) experiments, that molecular heterogeneity lowers bulk cooperativity from the intrinsic value for the individual molecules. As heterogeneity is common in smFRET experiments, appreciation of its influence on fundamental measures of cooperativity is critical for deriving accurate molecular models.

  11. Smart predictors in the heterogeneous agent model

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Vácha, Lukáš; Vošvrda, Miloslav

    2009-01-01

    Roč. 4, č. 2 (2009), s. 163-172 ISSN 1860-711X R&D Projects: GA ČR GP402/08/P207; GA ČR GA402/09/0965 Grant - others:GAUK(CZ) 46108 Institutional research plan: CEZ:AV0Z10750506 Keywords : Heterogeneous agent model * Market structure * Smart traders * Hurst exponent Subject RIV: AH - Economics

  12. Smart Agents and Sentiment in the Heterogeneous Agent Model

    Czech Academy of Sciences Publication Activity Database

    Vácha, Lukáš; Baruník, Jozef; Vošvrda, Miloslav

    -, č. 81 (2010), s. 39-40 ISSN 0926-4981 R&D Projects: GA ČR(CZ) GA402/09/0965; GA ČR GP402/08/P207 Grant - others:GAUK(CZ) GAUK 46108 Institutional research plan: CEZ:AV0Z10750506 Keywords : Smart traders * price movements * smart traders concept Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2010/E/vacha- smart agent s and sentiment in the heterogeneous agent model.pdf

  13. Evolution of Cooperation in Evolutionary Games for Heterogeneous Interactions

    International Nuclear Information System (INIS)

    Qian Xiaolan; Yang Junzhong

    2012-01-01

    When a population structure is modelled as a square lattice, the cooperation may be improved for an evolutionary prisoner dilemma game or be inhibited for an evolutionary snowdrift game. In this work, we investigate cooperation in a population on a square lattice where the interaction among players contains both prisoner dilemma game and snowdrift game. The heterogeneity in interaction is introduced to the population in two different ways: the heterogenous character of interaction assigned to every player (HCP) or the heterogenous character of interaction assigned to every link between any two players (HCL). The resonant enhancement of cooperation in the case of HCP is observed while the resonant inhibition of cooperation in the case of HCL is prominent. The explanations on the enhancement or inhibition of cooperation are presented for these two cases. (general)

  14. Multi-Agent Cooperative Target Search

    Directory of Open Access Journals (Sweden)

    Jinwen Hu

    2014-05-01

    Full Text Available This paper addresses a vision-based cooperative search for multiple mobile ground targets by a group of unmanned aerial vehicles (UAVs with limited sensing and communication capabilities. The airborne camera on each UAV has a limited field of view and its target discriminability varies as a function of altitude. First, by dividing the whole surveillance region into cells, a probability map can be formed for each UAV indicating the probability of target existence within each cell. Then, we propose a distributed probability map updating model which includes the fusion of measurement information, information sharing among neighboring agents, information decay and transmission due to environmental changes such as the target movement. Furthermore, we formulate the target search problem as a multi-agent cooperative coverage control problem by optimizing the collective coverage area and the detection performance. The proposed map updating model and the cooperative control scheme are distributed, i.e., assuming that each agent only communicates with its neighbors within its communication range. Finally, the effectiveness of the proposed algorithms is illustrated by simulation.

  15. Spatial snowdrift game in heterogeneous agent systems with co-evolutionary strategies and updating rules

    International Nuclear Information System (INIS)

    Xia Hai-Jiang; Li Ping-Ping; Ke Jian-Hong; Lin Zhen-Quan

    2015-01-01

    We propose an evolutionary snowdrift game model for heterogeneous systems with two types of agents, in which the inner-directed agents adopt the memory-based updating rule while the copycat-like ones take the unconditional imitation rule; moreover, each agent can change his type to adopt another updating rule once the number he sequentially loses the game at is beyond his upper limit of tolerance. The cooperative behaviors of such heterogeneous systems are then investigated by Monte Carlo simulations. The numerical results show the equilibrium cooperation frequency and composition as functions of the cost-to-benefit ratio r are both of plateau structures with discontinuous steplike jumps, and the number of plateaux varies non-monotonically with the upper limit of tolerance ν T as well as the initial composition of agents f a0 . Besides, the quantities of the cooperation frequency and composition are dependent crucially on the system parameters including ν T , f a0 , and r. One intriguing observation is that when the upper limit of tolerance is small, the cooperation frequency will be abnormally enhanced with the increase of the cost-to-benefit ratio in the range of 0 < r < 1/4. We then probe into the relative cooperation frequencies of either type of agents, which are also of plateau structures dependent on the system parameters. Our results may be helpful to understand the cooperative behaviors of heterogenous agent systems. (paper)

  16. Distributed Cooperative Control of Nonlinear and Non-identical Multi-agent Systems

    DEFF Research Database (Denmark)

    Bidram, Ali; Lewis, Frank; Davoudi, Ali

    2013-01-01

    This paper exploits input-output feedback linearization technique to implement distributed cooperative control of multi-agent systems with nonlinear and non-identical dynamics. Feedback linearization transforms the synchronization problem for a nonlinear and heterogeneous multi-agent system...... for electric power microgrids. The effectiveness of the proposed control is verified by simulating a microgrid test system....

  17. Multi-agent Cooperation in a Planning Framework

    NARCIS (Netherlands)

    De Weerdt, M.M.; Bos, A.; Tonino, J.F.M.; Witteveen, C.

    2000-01-01

    The promise of multi-agent systems is that multiple agents can solve problems more efficiently than single agents can. In this paper we propose a method to implement cooperation between agents in the planning phase, in order to achive more cost-effective solutions than without cooperation. Two

  18. Cooperative Radio Resource Management for Heterogeneous Networks

    DEFF Research Database (Denmark)

    Mihovska, Albena D.; Tragos, Elias; Luo, Jijun

    2009-01-01

    The heterogeneity in technology and also in ownership leads to complex systems and interworking problems, which can be seen from the ability to establish and maintain connections with required quality, in fault detection and location, in resource allocation and in charging of the usage of the net...

  19. Emergence of heterogeneity in an agent-based model

    OpenAIRE

    Abdullah, Wan Ahmad Tajuddin Wan

    2002-01-01

    We study an interacting agent model of a game-theoretical economy. The agents play a minority-subsequently-majority game and they learn, using backpropagation networks, to obtain higher payoffs. We study the relevance of heterogeneity to performance, and how heterogeneity emerges.

  20. Member Heterogeneity in Agricultural Cooperatives: A Systems-Theoretic Perspective

    Directory of Open Access Journals (Sweden)

    Constantine Iliopoulos

    2018-04-01

    Full Text Available All over the globe, cooperatives are plagued by pervasive member heterogeneity problems that are induced by the radical and dynamic changes in the business environment. Most current solutions to these problems emphasize strengthening member loyalty and commitment. Yet, many of these solutions are symptomatic rather than fundamental. Searching for fundamental solutions, this paper draws on the Luhmannian system-environment paradigm. Bringing this paradigm to bear on the cooperative scholarship, the paper views cooperatives as operationally closed systems maintaining a precarious relationship to their outer environment, which includes cooperative members. In view of their operational closure, cooperatives tend to overstrain the carrying capacity of their environment by being active in the areas marked by a limited extent of the true commonness of member interests. This overstraining results in a host of problems associated with member heterogeneity. The fundamental solutions following from the system-environment paradigm require the adjustment of cooperative boundaries and goals in light of the evolving range of the true common interests of members. In terms of methodology, we review the extant literature, synthesize the main elements of the system-environment approach and conduct a meta-analysis of case studies and other empirical research to highlight our theoretical arguments.

  1. Network flow of mobile agents enhances the evolution of cooperation

    Science.gov (United States)

    Ichinose, G.; Satotani, Y.; Nagatani, T.

    2018-01-01

    We study the effect of contingent movement on the persistence of cooperation on complex networks with empty nodes. Each agent plays the Prisoner's Dilemma game with its neighbors and then it either updates the strategy depending on the payoff difference with neighbors or it moves to another empty node if not satisfied with its own payoff. If no neighboring node is empty, each agent stays at the same site. By extensive evolutionary simulations, we show that the medium density of agents enhances cooperation where the network flow of mobile agents is also medium. Moreover, if the movements of agents are more frequent than the strategy updating, cooperation is further promoted. In scale-free networks, the optimal density for cooperation is lower than other networks because agents get stuck at hubs. Our study suggests that keeping a smooth network flow is significant for the persistence of cooperation in ever-changing societies.

  2. Monetary policy, banking and heterogeneous agents

    NARCIS (Netherlands)

    Wolski, M.

    2012-01-01

    The influence of heterogeneous expectations on monetary policy performance has gained a lot of attention in the recent years. It proved to be an important factor that, under some circumstances, may even destabilize the economy (Massaro, 2012). This paper investigates the phenomenon of heterogeneous

  3. Friendship-based partner switching promotes cooperation in heterogeneous populations

    Science.gov (United States)

    Chen, Wei; Wu, Te; Li, Zhiwu; Wang, Long

    2016-02-01

    The forming of human social ties tends to be with similar individuals. This study concentrates on the emergence of cooperation among heterogeneous populations. A simple model is proposed by considering the impact of interplay between the evolution of strategies and that of social partnerships on cooperation dynamics. Whenever two individuals acquire the rewards by playing prisoner's dilemma game with each other, the friendship (friendship is quantified as the weight of a link) between the two individuals deepens. Individuals can switch off the social ties with the partners who are unfriendly and rewire to similar new ones. Under this partner switching mechanism, population structure is divided into several groups and cooperation can prevail. It is observed that the frequent tendency of partner switching can lead to the enhancement of cooperative behavior under the enormous temptation to defect. Moreover, the influence of discounting the relationship between different individuals is also investigated. Meanwhile, the cooperation prevails when the adjustment of friendships mainly depends on the incomes of selected individuals rather than that of their partners. Finally, it is found that too similar population fail to maximize the cooperation and there exists a moderate similarity that can optimize cooperation.

  4. Heterogenous Agents Model with the Worst Out Algorithm

    Czech Academy of Sciences Publication Activity Database

    Vácha, Lukáš; Vošvrda, Miloslav

    -, č. 8 (2006), s. 3-19 ISSN 1801-5999 Institutional research plan: CEZ:AV0Z10750506 Keywords : efficient market hypothesis * fractal market hypothesis * agents' investment horizons * agents' trading strategies * technical trading rules * heterogeneous agent model with stochastic memory * Worst out algorithm Subject RIV: AH - Economics

  5. Consensus pursuit of heterogeneous multi-agent systems under a directed acyclic graph

    Science.gov (United States)

    Yan, Jing; Guan, Xin-Ping; Luo, Xiao-Yuan

    2011-04-01

    This paper is concerned with the cooperative target pursuit problem by multiple agents based on directed acyclic graph. The target appears at a random location and moves only when sensed by the agents, and agents will pursue the target once they detect its existence. Since the ability of each agent may be different, we consider the heterogeneous multi-agent systems. According to the topology of the multi-agent systems, a novel consensus-based control law is proposed, where the target and agents are modeled as a leader and followers, respectively. Based on Mason's rule and signal flow graph analysis, the convergence conditions are provided to show that the agents can catch the target in a finite time. Finally, simulation studies are provided to verify the effectiveness of the proposed approach.

  6. Heterogeneous agents and decison making within firms

    NARCIS (Netherlands)

    Hung, Chung-yu

    2015-01-01

    This dissertation explores the implications of agents’ heterogeneity in decision making within situations where information is not completely contractible. Specifically, the study applies empirical methods across three chapters to examine the role of employees’ traits and their mutual relationships

  7. Stochastic heterogeneous interaction promotes cooperation in spatial prisoner's dilemma game.

    Directory of Open Access Journals (Sweden)

    Ping Zhu

    Full Text Available Previous studies mostly investigate player's cooperative behavior as affected by game time-scale or individual diversity. In this paper, by involving both time-scale and diversity simultaneously, we explore the effect of stochastic heterogeneous interaction. In our model, the occurrence of game interaction between each pair of linked player obeys a random probability, which is further described by certain distributions. Simulations on a 4-neighbor square lattice show that the cooperation level is remarkably promoted when stochastic heterogeneous interaction is considered. The results are then explained by investigating the mean payoffs, the mean boundary payoffs and the transition probabilities between cooperators and defectors. We also show some typical snapshots and evolution time series of the system. Finally, the 8-neighbor square lattice and BA scale-free network results indicate that the stochastic heterogeneous interaction can be robust against different network topologies. Our work may sharpen the understanding of the joint effect of game time-scale and individual diversity on spatial games.

  8. The evolution of strong reciprocity: cooperation in heterogeneous populations.

    Science.gov (United States)

    Bowles, Samuel; Gintis, Herbert

    2004-02-01

    How do human groups maintain a high level of cooperation despite a low level of genetic relatedness among group members? We suggest that many humans have a predisposition to punish those who violate group-beneficial norms, even when this imposes a fitness cost on the punisher. Such altruistic punishment is widely observed to sustain high levels of cooperation in behavioral experiments and in natural settings. We offer a model of cooperation and punishment that we call STRONG RECIPROCITY: where members of a group benefit from mutual adherence to a social norm, strong reciprocators obey the norm and punish its violators, even though as a result they receive lower payoffs than other group members, such as selfish agents who violate the norm and do not punish, and pure cooperators who adhere to the norm but free-ride by never punishing. Our agent-based simulations show that, under assumptions approximating likely human environments over the 100000 years prior to the domestication of animals and plants, the proliferation of strong reciprocators when initially rare is highly likely, and that substantial frequencies of all three behavioral types can be sustained in a population. As a result, high levels of cooperation are sustained. Our results do not require that group members be related or that group extinctions occur.

  9. Heterogeneous agents and decison making within firms

    OpenAIRE

    Hung, Chung-yu

    2015-01-01

    This dissertation explores the implications of agents’ heterogeneity in decision making within situations where information is not completely contractible. Specifically, the study applies empirical methods across three chapters to examine the role of employees’ traits and their mutual relationships in decision making within firms. The first chapter investigates the association between managerial ability and managers’ discretionary bonus decisions using a dataset from a Chinese hospital and sh...

  10. Special Agents Can Promote Cooperation in the Population

    Science.gov (United States)

    Wang, Xin; Han, Jing; Han, Huawei

    2011-01-01

    Cooperation is ubiquitous in our real life but everyone would like to maximize her own profits. How does cooperation occur in the group of self-interested agents without centralized control? Furthermore, in a hostile scenario, for example, cooperation is unlikely to emerge. Is there any mechanism to promote cooperation if populations are given and play rules are not allowed to change? In this paper, numerical experiments show that complete population interaction is unfriendly to cooperation in the finite but end-unknown Repeated Prisoner's Dilemma (RPD). Then a mechanism called soft control is proposed to promote cooperation. According to the basic idea of soft control, a number of special agents are introduced to intervene in the evolution of cooperation. They comply with play rules in the original group so that they are always treated as normal agents. For our purpose, these special agents have their own strategies and share knowledge. The capability of the mechanism is studied under different settings. We find that soft control can promote cooperation and is robust to noise. Meanwhile simulation results demonstrate the applicability of the mechanism in other scenarios. Besides, the analytical proof also illustrates the effectiveness of soft control and validates simulation results. As a way of intervention in collective behaviors, soft control provides a possible direction for the study of reciprocal behaviors. PMID:22216202

  11. Heterogeneous game resource distributions promote cooperation in spatial prisoner's dilemma game

    Science.gov (United States)

    Cui, Guang-Hai; Wang, Zhen; Yang, Yan-Cun; Tian, Sheng-Wen; Yue, Jun

    2018-01-01

    In social networks, individual abilities to establish interactions are always heterogeneous and independent of the number of topological neighbors. We here study the influence of heterogeneous distributions of abilities on the evolution of individual cooperation in the spatial prisoner's dilemma game. First, we introduced a prisoner's dilemma game, taking into account individual heterogeneous abilities to establish games, which are determined by the owned game resources. Second, we studied three types of game resource distributions that follow the power-law property. Simulation results show that the heterogeneous distribution of individual game resources can promote cooperation effectively, and the heterogeneous level of resource distributions has a positive influence on the maintenance of cooperation. Extensive analysis shows that cooperators with large resource capacities can foster cooperator clusters around themselves. Furthermore, when the temptation to defect is high, cooperator clusters in which the central pure cooperators have larger game resource capacities are more stable than other cooperator clusters.

  12. Analysis of Bullying in Cooperative Multi-agent Systems’ Communications

    Directory of Open Access Journals (Sweden)

    Celia Gutiérrez

    2013-12-01

    Full Text Available Cooperative Multi-agent Systems frameworks do not include modules to test communications yet. The proposed framework incorporates robust analysis tools using IDKAnalysis2.0 to evaluate bullying effect in communications. The present work is based on ICARO-T. This platform follows the Adaptive Multi-agent Systems paradigm. Experimentation with ICARO-T includes two deployments: the equitative and the authoritative. Results confirm the usefulness of the analysis tools when exporting to Cooperative Multi-agent Systems that use different configurations. Besides, ICARO-T is provided with new functionality by a set of tools for communication analysis.

  13. Wavelets and Sentiment in the Heterogeneous Agents Model

    Czech Academy of Sciences Publication Activity Database

    Vácha, Lukáš; Vošvrda, Miloslav

    2008-01-01

    Roč. 15, č. 25 (2008), s. 41-56 ISSN 1212-074X R&D Projects: GA ČR GP402/08/P207; GA ČR GA402/07/1113; GA ČR(CZ) GA402/06/0990 Institutional research plan: CEZ:AV0Z10750506 Keywords : heterogeneous agents model * market sentiment * Hurst exponent * wavelets Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2008/E/vacha-wavelets and sentiment in the heterogeneous agents model.pdf

  14. Interntional Migration with Heterogeneous Agents: Theory and Evidence

    DEFF Research Database (Denmark)

    Schröder, Philipp J.H.; Brücker, Herbert

    Two puzzling facts of international migration are that only a small share of a sending country's population emigrates and that net migration rates tend to cease over time. This paper addresses these issues in a migration model with heterogeneous agents that features temporary migration...

  15. Heterogeneous Agent Model with Memory and Asset Price Behaviour

    Czech Academy of Sciences Publication Activity Database

    Vošvrda, Miloslav; Vácha, Lukáš

    2003-01-01

    Roč. 12, č. 2 (2003), s. 155-168 ISSN 1210-0455 R&D Projects: GA ČR GA402/00/0439; GA ČR GA402/01/0034 Institutional research plan: CEZ:AV0Z1075907 Keywords : efficient markets hypothesis * technical trading rules * heterogeneous agent model with memory and learning Subject RIV: AH - Economics

  16. Heterogeneous Agents Model with the Worst Out Algorithm

    Czech Academy of Sciences Publication Activity Database

    Vošvrda, Miloslav; Vácha, Lukáš

    I, č. 1 (2007), s. 54-66 ISSN 1802-4696 R&D Projects: GA MŠk(CZ) LC06075; GA ČR(CZ) GA402/06/0990 Grant - others:GA UK(CZ) 454/2004/A-EK/FSV Institutional research plan: CEZ:AV0Z10750506 Keywords : Efficient Market s Hypothesis * Fractal Market Hypothesis * agents' investment horizons * agents' trading strategies * technical trading rules * heterogeneous agent model with stochastic memory * Worst out Algorithm Subject RIV: AH - Economics

  17. Multicell Cooperation for LTE-Advanced Heterogeneous Network Scenarios

    DEFF Research Database (Denmark)

    Soret, Beatriz; Wang, Hua; Rosa, Claudio

    2013-01-01

    In this article we present two promising practical use cases for simple multicell cooperation for LTE-Advanced heterogeneous network (HetNet) scenarios with macro and small cells. For co-channel deployment cases, we recommend the use of enhanced inter-cell interference coordination (e......ICIC) to mitigate cross-tier interference and ensure sufficient offload of users from macro to small cells. It is shown how the eICIC benefit is maximized by using a distributed inter-base station control framework for dynamic adjustment of essential parameters. Secondly, for scenarios where macro and small cells...... are deployed at different carriers an efficient use of the fragmented spectrum can be achieved by using collaborative inter-site carrier aggregation. In addition to distributed coordination/collaboration between base station nodes, the importance of explicit terminal assistance is highlighted. Comprehensive...

  18. Interactive macroeconomics stochastic aggregate dynamics with heterogeneous and interacting agents

    CERN Document Server

    Di Guilmi, Corrado

    2017-01-01

    One of the major problems of macroeconomic theory is the way in which the people exchange goods in decentralized market economies. There are major disagreements among macroeconomists regarding tools to influence required outcomes. Since the mainstream efficient market theory fails to provide an internal coherent framework, there is a need for an alternative theory. The book provides an innovative approach for the analysis of agent based models, populated by the heterogeneous and interacting agents in the field of financial fragility. The text is divided in two parts; the first presents analytical developments of stochastic aggregation and macro-dynamics inference methods. The second part introduces macroeconomic models of financial fragility for complex systems populated by heterogeneous and interacting agents. The concepts of financial fragility and macroeconomic dynamics are explained in detail in separate chapters. The statistical physics approach is applied to explain theories of macroeconomic modelling a...

  19. Robust output synchronization of heterogeneous nonlinear agents in uncertain networks.

    Science.gov (United States)

    Yang, Xi; Wan, Fuhua; Tu, Mengchuan; Shen, Guojiang

    2017-11-01

    This paper investigates the global robust output synchronization problem for a class of nonlinear multi-agent systems. In the considered setup, the controlled agents are heterogeneous and with both dynamic and parametric uncertainties, the controllers are incapable of exchanging their internal states with the neighbors, and the communication network among agents is defined by an uncertain simple digraph. The problem is pursued via nonlinear output regulation theory and internal model based design. For each agent, the input-driven filter and the internal model compose the controller, and the decentralized dynamic output feedback control law is derived by using backstepping method and the modified dynamic high-gain technique. The theoretical result is applied to output synchronization problem for uncertain network of Lorenz-type agents. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  20. Multi-agent cooperation for particle accelerator control

    CERN Document Server

    Skarek, Paul

    1996-01-01

    We present practical investigations in a real industrial controls environment for justifying theoretical DAI (Distributed Artificial Intelligence) results, and we discuss theoretical aspects of practical investigations for accelerator control and operation. A generalized hypothesis is introduced based on a unified view of control, monitoring, diagnosis, maintenance and repair tasks leading to a general method of cooperation for expert systems by exchanging hypotheses. This has been tested for task and result sharing cooperation scenarios. Generalized hypotheses also allow us to treat the repetitive diagnosis-recovery cycle as task sharing cooperation. Problems with such a loop or even recursive calls between the different agents are discussed.

  1. Heterogeneous aspirations promote cooperation in the prisoner's dilemma game.

    Directory of Open Access Journals (Sweden)

    Matjaž Perc

    2010-12-01

    Full Text Available To be the fittest is central to proliferation in evolutionary games. Individuals thus adopt the strategies of better performing players in the hope of successful reproduction. In structured populations the array of those that are eligible to act as strategy sources is bounded to the immediate neighbors of each individual. But which one of these strategy sources should potentially be copied? Previous research dealt with this question either by selecting the fittest or by selecting one player uniformly at random. Here we introduce a parameter u that interpolates between these two extreme options. Setting u equal to zero returns the random selection of the opponent, while positive u favor the fitter players. In addition, we divide the population into two groups. Players from group A select their opponents as dictated by the parameter u, while players from group B do so randomly irrespective of u. We denote the fraction of players contained in groups A and B by v and 1 - v, respectively. The two parameters u and v allow us to analyze in detail how aspirations in the context of the prisoner’s dilemma game influence the evolution of cooperation. We find that for sufficiently positive values of u there exist a robust intermediate v ≈ 0.5 for which cooperation thrives best. The robustness of this observation is tested against different levels of uncertainty in the strategy adoption process K and for different interaction networks. We also provide complete phase diagrams depicting the dependence of the impact of u and v for different values of K, and contrast the validity of our conclusions by means of an alternative model where individual aspiration levels are subject to evolution as well. Our study indicates that heterogeneity in aspirations may be key for the sustainability of cooperation in structured populations.

  2. Agent-based land markets: Heterogeneous agents, land proces and urban land use change

    NARCIS (Netherlands)

    Filatova, Tatiana; Parker, Dawn C.; van der Veen, A.; Amblard, F.

    2007-01-01

    We construct a spatially explicit agent-based model of a bilateral land market. Heterogeneous agents form their bid and ask prices for land based on the utility that they obtain from a certain location (houte/land) and base on the state of the market (an excess of demand or supply). We underline the

  3. Percolation and cooperation with mobile agents: geometric and strategy clusters.

    Science.gov (United States)

    Vainstein, Mendeli H; Brito, Carolina; Arenzon, Jeferson J

    2014-08-01

    We study the conditions for persistent cooperation in an off-lattice model of mobile agents playing the Prisoner's Dilemma game with pure, unconditional strategies. Each agent has an exclusion radius r(P), which accounts for the population viscosity, and an interaction radius r(int), which defines the instantaneous contact network for the game dynamics. We show that, differently from the r(P)=0 case, the model with finite-sized agents presents a coexistence phase with both cooperators and defectors, besides the two absorbing phases, in which either cooperators or defectors dominate. We provide, in addition, a geometric interpretation of the transitions between phases. In analogy with lattice models, the geometric percolation of the contact network (i.e., irrespective of the strategy) enhances cooperation. More importantly, we show that the percolation of defectors is an essential condition for their survival. Differently from compact clusters of cooperators, isolated groups of defectors will eventually become extinct if not percolating, independently of their size.

  4. Semi-Cooperative Learning in Smart Grid Agents

    Science.gov (United States)

    2013-12-01

    this PhD program , but watching you grow has only made me realize how much more awesome human learning is. You have been a source of profound joy and...which should alleviate concern for scala - bility along this dimension. • Learning the negotiation model: Figure 6.23 shows single-episode results that...for Semi-cooperative Multi-agent Coordination. In IEEE Symposium on Adaptive Dynamic Programming and Reinforcement Learning . [Prendergast, 1999

  5. Statistical mechanics of socio-economic systems with heterogeneous agents

    International Nuclear Information System (INIS)

    De Martino, Andrea; Marsili, Matteo

    2006-01-01

    We review the statistical mechanics approach to the study of the emerging collective behaviour of systems of heterogeneous interacting agents. The general framework is presented through examples in such contexts as ecosystem dynamics and traffic modelling. We then focus on the analysis of the optimal properties of large random resource-allocation problems and on Minority Games and related models of speculative trading in financial markets, discussing a number of extensions including multi-asset models, majority games and models with asymmetric information. Finally, we summarize the main conclusions and outline the major open problems and limitations of the approach. (topical review)

  6. Effect of heterogeneous investments on the evolution of cooperation in spatial public goods game.

    Science.gov (United States)

    Huang, Keke; Wang, Tao; Cheng, Yuan; Zheng, Xiaoping

    2015-01-01

    Understanding the emergence of cooperation in spatial public goods game remains a grand challenge across disciplines. In most previous studies, it is assumed that the investments of all the cooperators are identical, and often equal to 1. However, it is worth mentioning that players are diverse and heterogeneous when choosing actions in the rapidly developing modern society and researchers have shown more interest to the heterogeneity of players recently. For modeling the heterogeneous players without loss of generality, it is assumed in this work that the investment of a cooperator is a random variable with uniform distribution, the mean value of which is equal to 1. The results of extensive numerical simulations convincingly indicate that heterogeneous investments can promote cooperation. Specifically, a large value of the variance of the random variable can decrease the two critical values for the result of behavioral evolution effectively. Moreover, the larger the variance is, the better the promotion effect will be. In addition, this article has discussed the impact of heterogeneous investments when the coevolution of both strategy and investment is taken into account. Comparing the promotion effect of coevolution of strategy and investment with that of strategy imitation only, we can conclude that the coevolution of strategy and investment decreases the asymptotic fraction of cooperators by weakening the heterogeneity of investments, which further demonstrates that heterogeneous investments can promote cooperation in spatial public goods game.

  7. Dynamic aggregation evolution of competitive societies of cooperative and noncooperative agents

    International Nuclear Information System (INIS)

    Lin Zhen-Quan; Ye Gao-Xiang

    2013-01-01

    We propose an evolution model of cooperative agent and noncooperative agent aggregates to investigate the dynamic evolution behaviors of the system and the effects of the competing microscopic reactions on the dynamic evolution. In this model, each cooperative agent and noncooperative agent are endowed with integer values of cooperative spirits and noncooperative spirits, respectively. The cooperative spirits of a cooperative agent aggregate and the noncooperative spirits of a noncooperative agent aggregate change via four competing microscopic reaction schemes: the win-win reaction between two cooperative agents, the lose-lose reaction between two noncooperative agents, the win-lose reaction between a cooperative agent and a noncooperative agent (equivalent to the migration of spirits from cooperative agents to noncooperative agents), and the cooperative agent catalyzed decline of noncooperative spirits. Based on the generalized Smoluchowski's rate equation approach, we investigate the dynamic evolution behaviors such as the total cooperative spirits of all cooperative agents and the total noncooperative spirits of all noncooperative agents. The effects of the three main groups of competition on the dynamic evolution are revealed. These include: (i) the competition between the lose-lose reaction and the win-lose reaction, which gives rise to respectively the decrease and increase in the noncooperative agent spirits; (ii) the competition between the win-win reaction and the win-lose reaction, which gives rise to respectively the increase and decrease in the cooperative agent spirits; (iii) the competition between the win-lose reaction and the catalyzed-decline reaction, which gives rise to respectively the increase and decrease in the noncooperative agent spirits. (interdisciplinary physics and related areas of science and technology)

  8. An event-triggered control approach for the leader-tracking problem with heterogeneous agents

    Science.gov (United States)

    Garcia, Eloy; Cao, Yongcan; Casbeer, David W.

    2018-05-01

    This paper presents an event-triggered control and communication framework for the cooperative leader-tracking problem with communication constraints. Continuous communication among agents is not assumed in this work and decentralised event-based strategies are proposed for agents with heterogeneous linear dynamics. Also, the leader dynamics are unknown and only intermittent measurements of its states are obtained by a subset of the followers. The event-based method not only represents a way to restrict communication among agents, but it also provides a decentralised scheme for scheduling information broadcasts. Notably, each agent is able to determine its own broadcasting instants independently of any other agent in the network. In an extension, the case where transmission of information is affected by time-varying communication delays is addressed. Finally, positive lower-bounds on the inter-event time intervals are obtained in order to show that Zeno behaviour does not exist and, therefore, continuous exchange of information is never needed in this framework.

  9. Evolution of cooperation in a heterogeneous population with influential individuals

    Science.gov (United States)

    Zhuang, Qian; Wang, Dong; Fan, Ying; Di, Zengru

    2012-02-01

    Influential individuals are introduced and integrated with the public goods game (PGG) to investigate their influence on the emergence and evolution of cooperation. In the model, some influential individuals whose behaviors can be controlled by us are introduced into a homogeneous population on a square lattice. The influential individuals can play three kinds of roles: I. exemplar, II. supervisor with the power to punish defectors, and III. supervisor with the power to reward cooperative co-players. It is found that the existence of influential individuals who play Role I turns out to be detrimental to cooperation and that the larger the number of influential individuals is, the more difficult it is for cooperation to be maintained. For those playing supervisory roles, both punishment and reward are found to be effective ways for the influential individuals to promote and stabilize cooperative behavior. By comparing the critical costs and the mean payoffs for a low multiplication factor under the role of punishment and the role of reward, it is found that reward is a more effective intervention measure than punishment for influential individuals seeking to improve cooperation and that reward leads to a higher mean payoff.

  10. International Migration with Heterogeneous Agents: Theory and Evidence

    DEFF Research Database (Denmark)

    Schröder, Philipp J.H.; Brücker, Herbert

    Temporary migration, though empirically relevant, is often ignored in formal models. This paper proposes a migration model with heterogeneous agents and persistent cross country income differentials that features temporary migration. In equilibrium there exists a positive relation between the stock...... of migrants and the income differential, while the net migration flow becomes zero. Consequently, existing empirical migration models, estimating net migration flows, instead of stocks, may be misspecified. This suspicion appears to be confirmed by our investigation of the cointegration relationships...... of German migration stocks and flows since 1967. We find that (i) panel-unit root tests reject the hypothesis that migration flows and the explanatory variables are integrated of the same order, while migration stocks and the explanatory variables are all I(1) variables, and (ii) the hypothesis...

  11. Stylized facts from a threshold-based heterogeneous agent model

    Science.gov (United States)

    Cross, R.; Grinfeld, M.; Lamba, H.; Seaman, T.

    2007-05-01

    A class of heterogeneous agent models is investigated where investors switch trading position whenever their motivation to do so exceeds some critical threshold. These motivations can be psychological in nature or reflect behaviour suggested by the efficient market hypothesis (EMH). By introducing different propensities into a baseline model that displays EMH behaviour, one can attempt to isolate their effects upon the market dynamics. The simulation results indicate that the introduction of a herding propensity results in excess kurtosis and power-law decay consistent with those observed in actual return distributions, but not in significant long-term volatility correlations. Possible alternatives for introducing such long-term volatility correlations are then identified and discussed.

  12. The effect of heterogeneous defectors on the evolution of public cooperation

    Science.gov (United States)

    Chen, Tong; Hu, Xuezhi; Wang, Yongjie; Wang, Le

    2018-06-01

    In recent years,more and more private capital join the construction of cultural facilities and the organization of cultural activities in China. Actually, the organization of cultural activities by crowd-funding mechanism is a kind of multi-player game. Not all players who donate different amount of money are real cooperators. In fact, some cunning defectors may donate a little money to avoid the gossip and punishment. This part of people are very tricky. They could be seen as heterogeneous defectors. The role of heterogeneous defectors is investigated in cooperative behaviors of complex social network. Numerical results show that heterogeneous defectors could be a buffer for maintaining the public pool when synergy factor is low in public goods game (PGG). It is relatively easy to be cooperators for heterogeneous defectors when synergy factor is high in PGG. To better improve cooperation, punishment towards heterogeneous defectors and complete defectors is introduced. We are glad to find that when the defectors' loss is equal to or larger than the altruistic cooperators' punishment cost, the mechanism could make great effect. In addition, the role of heterogeneous defectors depends on the relationship between the punishment cost and the defectors' loss.

  13. Conformity-based cooperation in online social networks: The effect of heterogeneous social influence

    International Nuclear Information System (INIS)

    Xu, Bo; Wang, Jianwei; Zhang, Xuejun

    2015-01-01

    This paper extends the conformity model by introducing heterogeneous social influence into the analysis. We associate the influence of a player in the network with its degree centrality assuming that players of higher degree exhibit more social influence on its neighbors. The results show that the equilibrium level of cooperators can be dramatically enhanced if the conformity-driven players are preferentially influenced by neighbors of higher degree. We attribute this finding to two elementary mechanisms in the evolutionary process: (1) degree-based social influence facilitates the formation of strategic clusters around hubs; and (2) payoff-heterogeneity between cooperative clusters and defective clusters contributes to the promotion of cooperation. This research reveals the important role of heterogeneous social influence on the emergence of cooperation in social networks.

  14. Cooperative control of multi-agent systems optimal and adaptive design approaches

    CERN Document Server

    Lewis, Frank L; Hengster-Movric, Kristian; Das, Abhijit

    2014-01-01

    Task complexity, communication constraints, flexibility and energy-saving concerns are all factors that may require a group of autonomous agents to work together in a cooperative manner. Applications involving such complications include mobile robots, wireless sensor networks, unmanned aerial vehicles (UAVs), spacecraft, and so on. In such networked multi-agent scenarios, the restrictions imposed by the communication graph topology can pose severe problems in the design of cooperative feedback control systems.  Cooperative control of multi-agent systems is a challenging topic for both control theorists and practitioners and has been the subject of significant recent research. Cooperative Control of Multi-Agent Systems extends optimal control and adaptive control design methods to multi-agent systems on communication graphs.  It develops Riccati design techniques for general linear dynamics for cooperative state feedback design, cooperative observer design, and cooperative dynamic output feedback design.  B...

  15. Multi-agent cooperative systems applied to precision applications

    International Nuclear Information System (INIS)

    McKay, M.D.; Anderson, M.O.; Gunderson, R.W.; Flann, N.; Abbott, B.

    1998-01-01

    Regulatory agencies are imposing limits and constraints to protect the operator and/or the environment. While generally necessary, these controls also tend to increase cost and decrease efficiency and productivity. Intelligent computer systems can be made to perform these hazardous tasks with greater efficiency and precision without danger to the operators. The Idaho national Engineering and Environmental Laboratory and the Center for Self-Organizing and Intelligent Systems at Utah State University have developed a series of autonomous all-terrain multi-agent systems capable of performing automated tasks within hazardous environments. This paper discusses the development and application of cooperative small-scale and large-scale robots for use in various activities associated with radiologically contaminated areas, prescription farming, and unexploded ordinances

  16. Heterogeneous Coupling between Interdependent Lattices Promotes the Cooperation in the Prisoner's Dilemma Game.

    Science.gov (United States)

    Xia, Cheng-Yi; Meng, Xiao-Kun; Wang, Zhen

    2015-01-01

    In the research realm of game theory, interdependent networks have extended the content of spatial reciprocity, which needs the suitable coupling between networks. However, thus far, the vast majority of existing works just assume that the coupling strength between networks is symmetric. This hypothesis, to some extent, seems inconsistent with the ubiquitous observation of heterogeneity. Here, we study how the heterogeneous coupling strength, which characterizes the interdependency of utility between corresponding players of both networks, affects the evolution of cooperation in the prisoner's dilemma game with two types of coupling schemes (symmetric and asymmetric ones). Compared with the traditional case, we show that heterogeneous coupling greatly promotes the collective cooperation. The symmetric scheme seems much better than the asymmetric case. Moreover, the role of varying amplitude of coupling strength is also studied on these two interdependent ways. Current findings are helpful for us to understand the evolution of cooperation within many real-world systems, in particular for the interconnected and interrelated systems.

  17. Wealth Share Analysis with “Fundamentalist/Chartist” Heterogeneous Agents

    Directory of Open Access Journals (Sweden)

    Hai-Chuan Xu

    2014-01-01

    Full Text Available We build a multiassets heterogeneous agents model with fundamentalists and chartists, who make investment decisions by maximizing the constant relative risk aversion utility function. We verify that the model can reproduce the main stylized facts in real markets, such as fat-tailed return distribution and long-term memory in volatility. Based on the calibrated model, we study the impacts of the key strategies’ parameters on investors’ wealth shares. We find that, as chartists’ exponential moving average periods increase, their wealth shares also show an increasing trend. This means that higher memory length can help to improve their wealth shares. This effect saturates when the exponential moving average periods are sufficiently long. On the other hand, the mean reversion parameter has no obvious impacts on wealth shares of either type of traders. It suggests that no matter whether fundamentalists take moderate strategy or aggressive strategy on the mistake of stock prices, it will have no different impact on their wealth shares in the long run.

  18. Role of investment heterogeneity in the cooperation on spatial public goods game.

    Science.gov (United States)

    Yuan, Wu-Jie; Xia, Cheng-Yi

    2014-01-01

    Public cooperation plays a significant role in the survival and maintenance of biological species, to elucidate its origin thus becomes an interesting question from various disciplines. Through long-term development, the public goods game has proven to be a useful tool, where cooperator making contribution can beat again the free-rides. Differentiating from the traditional homogeneous investment, individual trend of making contribution is more likely affected by the investment level of his neighborhood. Based on this fact, we here investigate the impact of heterogeneous investment on public cooperation, where the investment sum is mapped to the proportion of cooperators determined by parameter α. Interestingly, we find, irrespective of interaction networks, that the increment of α (increment of heterogeneous investment) is beneficial for promoting cooperation and even guarantees the complete cooperation dominance under weak replication factor. While this promotion effect can be attributed to the formation of more robust cooperator clusters and shortening END period. Moreover, we find that this simple mechanism can change the potential interaction network, which results in the change of phase diagrams. We hope that our work may shed light on the understanding of the cooperative behavior in other social dilemmas.

  19. Evolutionary mixed games in structured populations: Cooperation and the benefits of heterogeneity

    Science.gov (United States)

    Amaral, Marco A.; Wardil, Lucas; Perc, Matjaž; da Silva, Jafferson K. L.

    2016-04-01

    Evolutionary games on networks traditionally involve the same game at each interaction. Here we depart from this assumption by considering mixed games, where the game played at each interaction is drawn uniformly at random from a set of two different games. While in well-mixed populations the random mixture of the two games is always equivalent to the average single game, in structured populations this is not always the case. We show that the outcome is, in fact, strongly dependent on the distance of separation of the two games in the parameter space. Effectively, this distance introduces payoff heterogeneity, and the average game is returned only if the heterogeneity is small. For higher levels of heterogeneity the distance to the average game grows, which often involves the promotion of cooperation. The presented results support preceding research that highlights the favorable role of heterogeneity regardless of its origin, and they also emphasize the importance of the population structure in amplifying facilitators of cooperation.

  20. An Erbium-Based Bifuctional Heterogeneous Catalyst: A Cooperative Route Towards C-C Bond Formation

    Directory of Open Access Journals (Sweden)

    Manuela Oliverio

    2014-07-01

    Full Text Available Heterogeneous bifuctional catalysts are multifunctional synthetic catalysts enabling efficient organic transformations by exploiting two opposite functionalities without mutual destruction. In this paper we report the first Er(III-based metallorganic heterogeneous catalyst, synthesized by post-calcination MW-assisted grafting and modification of the natural aminoacid L-cysteine. The natural acid–base distance between sites was maintained to assure the cooperation. The applicability of this new bifunctional heterogeneous catalyst to C-C bond formation and the supposed mechanisms of action are discussed as well.

  1. Cellular image segmentation using n-agent cooperative game theory

    Science.gov (United States)

    Dimock, Ian B.; Wan, Justin W. L.

    2016-03-01

    Image segmentation is an important problem in computer vision and has significant applications in the segmentation of cellular images. Many different imaging techniques exist and produce a variety of image properties which pose difficulties to image segmentation routines. Bright-field images are particularly challenging because of the non-uniform shape of the cells, the low contrast between cells and background, and imaging artifacts such as halos and broken edges. Classical segmentation techniques often produce poor results on these challenging images. Previous attempts at bright-field imaging are often limited in scope to the images that they segment. In this paper, we introduce a new algorithm for automatically segmenting cellular images. The algorithm incorporates two game theoretic models which allow each pixel to act as an independent agent with the goal of selecting their best labelling strategy. In the non-cooperative model, the pixels choose strategies greedily based only on local information. In the cooperative model, the pixels can form coalitions, which select labelling strategies that benefit the entire group. Combining these two models produces a method which allows the pixels to balance both local and global information when selecting their label. With the addition of k-means and active contour techniques for initialization and post-processing purposes, we achieve a robust segmentation routine. The algorithm is applied to several cell image datasets including bright-field images, fluorescent images and simulated images. Experiments show that the algorithm produces good segmentation results across the variety of datasets which differ in cell density, cell shape, contrast, and noise levels.

  2. Individual choice and reputation distribution of cooperative behaviors among heterogeneous groups

    International Nuclear Information System (INIS)

    Lu, Peng

    2015-01-01

    Highlights: •Cooperation macrocosmically refers to the overall cooperation rate, while reputation microcosmically records individual choices. •Therefore, reputation should be preferred in order to investigate how individual choices evolve. •Both the mean and standard deviation of reputation follow clear patterns, and some factors have quadratic effects on them. -- Abstract: Cooperation is vital for our society, but the temptation of cheating on cooperative partners undermines cooperation. The mechanism of reputation is raised to countervail this temptation and therefore promote cooperation. Reputation microcosmically records individual choices, while cooperation macrocosmically refers to the group or averaged cooperation level. Reputation should be preferred in order to investigate how individual choices evolve. In this work, we study the distribution of reputation to figure out how individuals make choices within cooperation and defection. We decompose reputation into its mean and standard deviation and inspect effects of their factors respectively. To achieve this goal, we construct a model where agents of three groups or classes play the prisoners’ dilemma game with neighbors on a square lattice. It indicates in outcomes that the distribution of reputation is distinct from that of cooperation and both the mean and standard deviation of reputation follow clear patterns. Some factors have negative quadratic effects on reputation's mean or standard deviation, and some have merely linear effects

  3. Effects of heterogeneous wealth distribution on public cooperation with collective risk

    Science.gov (United States)

    Wang, Jing; Fu, Feng; Wang, Long

    2010-07-01

    The distribution of wealth among individuals in real society can be well described by the Pareto principle or “80-20 rule.” How does such heterogeneity in initial wealth distribution affect the emergence of public cooperation, when individuals, the rich and the poor, engage in a collective-risk enterprise, not to gain a profit but to avoid a potential loss? Here we address this issue by studying a simple but effective model based on threshold public goods games. We analyze the evolutionary dynamics for two distinct scenarios, respectively: one with fair sharers versus defectors and the other with altruists versus defectors. For both scenarios, particularly, we in detail study the dynamics of the population with dichotomic initial wealth—the rich versus the poor. Moreover, we demonstrate the possible steady compositions of the population and provide the conditions for stability of these steady states. We prove that in a population with heterogeneous wealth distribution, richer individuals are more likely to cooperate than poorer ones. Participants with lower initial wealth may choose to cooperate only if all players richer than them are cooperators. The emergence of pubic cooperation largely relies on rich individuals. Furthermore, whenever the wealth gap between the rich and the poor is sufficiently large, cooperation of a few rich individuals can substantially elevate the overall level of social cooperation, which is in line with the well-known Pareto principle. Our work may offer an insight into the emergence of cooperative behavior in real social situations where heterogeneous distribution of wealth among individual is omnipresent.

  4. Effects of heterogeneous wealth distribution on public cooperation with collective risk.

    Science.gov (United States)

    Wang, Jing; Fu, Feng; Wang, Long

    2010-07-01

    The distribution of wealth among individuals in real society can be well described by the Pareto principle or "80-20 rule." How does such heterogeneity in initial wealth distribution affect the emergence of public cooperation, when individuals, the rich and the poor, engage in a collective-risk enterprise, not to gain a profit but to avoid a potential loss? Here we address this issue by studying a simple but effective model based on threshold public goods games. We analyze the evolutionary dynamics for two distinct scenarios, respectively: one with fair sharers versus defectors and the other with altruists versus defectors. For both scenarios, particularly, we in detail study the dynamics of the population with dichotomic initial wealth-the rich versus the poor. Moreover, we demonstrate the possible steady compositions of the population and provide the conditions for stability of these steady states. We prove that in a population with heterogeneous wealth distribution, richer individuals are more likely to cooperate than poorer ones. Participants with lower initial wealth may choose to cooperate only if all players richer than them are cooperators. The emergence of pubic cooperation largely relies on rich individuals. Furthermore, whenever the wealth gap between the rich and the poor is sufficiently large, cooperation of a few rich individuals can substantially elevate the overall level of social cooperation, which is in line with the well-known Pareto principle. Our work may offer an insight into the emergence of cooperative behavior in real social situations where heterogeneous distribution of wealth among individual is omnipresent.

  5. A QUANTITATIVE FRAMEWORK FOR EARLY PREDICTION OF COOPERATION IN MULTI-AGENT SYSTEMS

    Directory of Open Access Journals (Sweden)

    S. Ajitha

    2013-07-01

    Full Text Available A Multi-Agent System (MAS is a system composed of multiple interacting intelligent agents. MAS can be used to solve problems that are difficult or impossible for an individual agent to solve. The different characteristics of MAS help in solving highly complex distributed problems. One of the important characteristics of MAS is its cooperative nature. This character helps different agents to interact with each other by exchanging messages. One of the major challenges in MAS is quantifying the cooperation between agents. This paper presents a framework for the quantification of cooperation between agents in MAS. We propose a methodology which helps to quantify the cooperation in the early stages of software development using a UML sequence diagram and a mathematical model. The proposed techniques are illustrated with the help of a case study. The numerical results we got were quite satisfactory.

  6. Robust Architectures for Complex Multi-Agent Heterogeneous Systems

    Science.gov (United States)

    2014-07-23

    cooperative trajectory generation framework with account of spatial and temporal constraints [2], and iii) developing a decoupled architecture for...in the presence of dynamic information flow and quantized measurements [1], ii) developing a cooperative trajectory generation framework with account ... CIE 2013, Portland, OR, DETC2013-12744, 2013 (one of the five finalists for “best student paper award”). 8. R. Choe, V. Cichella, E. Xargay, N

  7. Consensus of heterogeneous multi-agent systems based on sampled data with a small sampling delay

    International Nuclear Information System (INIS)

    Wang Na; Wu Zhi-Hai; Peng Li

    2014-01-01

    In this paper, consensus problems of heterogeneous multi-agent systems based on sampled data with a small sampling delay are considered. First, a consensus protocol based on sampled data with a small sampling delay for heterogeneous multi-agent systems is proposed. Then, the algebra graph theory, the matrix method, the stability theory of linear systems, and some other techniques are employed to derive the necessary and sufficient conditions guaranteeing heterogeneous multi-agent systems to asymptotically achieve the stationary consensus. Finally, simulations are performed to demonstrate the correctness of the theoretical results. (interdisciplinary physics and related areas of science and technology)

  8. Multi-agent cooperation rescue algorithm based on influence degree and state prediction

    Science.gov (United States)

    Zheng, Yanbin; Ma, Guangfu; Wang, Linlin; Xi, Pengxue

    2018-04-01

    Aiming at the multi-agent cooperative rescue in disaster, a multi-agent cooperative rescue algorithm based on impact degree and state prediction is proposed. Firstly, based on the influence of the information in the scene on the collaborative task, the influence degree function is used to filter the information. Secondly, using the selected information to predict the state of the system and Agent behavior. Finally, according to the result of the forecast, the cooperative behavior of Agent is guided and improved the efficiency of individual collaboration. The simulation results show that this algorithm can effectively solve the cooperative rescue problem of multi-agent and ensure the efficient completion of the task.

  9. Heterogeneous Coupling between Interdependent Lattices Promotes the Cooperation in the Prisoner's Dilemma Game.

    Directory of Open Access Journals (Sweden)

    Cheng-Yi Xia

    Full Text Available In the research realm of game theory, interdependent networks have extended the content of spatial reciprocity, which needs the suitable coupling between networks. However, thus far, the vast majority of existing works just assume that the coupling strength between networks is symmetric. This hypothesis, to some extent, seems inconsistent with the ubiquitous observation of heterogeneity. Here, we study how the heterogeneous coupling strength, which characterizes the interdependency of utility between corresponding players of both networks, affects the evolution of cooperation in the prisoner's dilemma game with two types of coupling schemes (symmetric and asymmetric ones. Compared with the traditional case, we show that heterogeneous coupling greatly promotes the collective cooperation. The symmetric scheme seems much better than the asymmetric case. Moreover, the role of varying amplitude of coupling strength is also studied on these two interdependent ways. Current findings are helpful for us to understand the evolution of cooperation within many real-world systems, in particular for the interconnected and interrelated systems.

  10. Modelling complex systems of heterogeneous agents to better design sustainability transitions policy

    NARCIS (Netherlands)

    Mercure, J.F.A.; Pollitt, H.; Bassi, A.M.; Viñuales, J.E.; Edwards, N.R.

    2016-01-01

    This article proposes a fundamental methodological shift in the modelling of policy interventions for sustainability transitions in order to account for complexity (e.g. self-reinforcing mechanisms, such as technology lock-ins, arising from multi-agent interactions) and agent heterogeneity (e.g.

  11. Bacteria and game theory: the rise and fall of cooperation in spatially heterogeneous environments.

    Science.gov (United States)

    Lambert, Guillaume; Vyawahare, Saurabh; Austin, Robert H

    2014-08-06

    One of the predictions of game theory is that cooperative behaviours are vulnerable to exploitation by selfish individuals, but this result seemingly contradicts the survival of cooperation observed in nature. In this review, we will introduce game theoretical concepts that lead to this conclusion and show how the spatial competition dynamics between microorganisms can be used to model the survival and maintenance of cooperation. In particular, we focus on how Escherichia coli bacteria with a growth advantage in stationary phase (GASP) phenotype maintain a proliferative phenotype when faced with overcrowding to gain a fitness advantage over wild-type populations. We review recent experimental approaches studying the growth dynamics of competing GASP and wild-type strains of E. coli inside interconnected microfabricated habitats and use a game theoretical approach to analyse the observed inter-species interactions. We describe how the use of evolutionary game theory and the ideal free distribution accurately models the spatial distribution of cooperative and selfish individuals in spatially heterogeneous environments. Using bacteria as a model system of cooperative and selfish behaviours may lead to a better understanding of the competition dynamics of other organisms-including tumour-host interactions during cancer development and metastasis.

  12. ALLIANCE: An architecture for fault tolerant, cooperative control of heterogeneous mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Parker, L.E.

    1995-02-01

    This research addresses the problem of achieving fault tolerant cooperation within small- to medium-sized teams of heterogeneous mobile robots. The author describes a novel behavior-based, fully distributed architecture, called ALLIANCE, that utilizes adaptive action selection to achieve fault tolerant cooperative control in robot missions involving loosely coupled, largely independent tasks. The robots in this architecture possess a variety of high-level functions that they can perform during a mission, and must at all times select an appropriate action based on the requirements of the mission, the activities of other robots, the current environmental conditions, and their own internal states. Since such cooperative teams often work in dynamic and unpredictable environments, the software architecture allows the team members to respond robustly and reliably to unexpected environmental changes and modifications in the robot team that may occur due to mechanical failure, the learning of new skills, or the addition or removal of robots from the team by human intervention. After presenting ALLIANCE, the author describes in detail experimental results of an implementation of this architecture on a team of physical mobile robots performing a cooperative box pushing demonstration. These experiments illustrate the ability of ALLIANCE to achieve adaptive, fault-tolerant cooperative control amidst dynamic changes in the capabilities of the robot team.

  13. Multi-Objective Clustering Optimization for Multi-Channel Cooperative Spectrum Sensing in Heterogeneous Green CRNs

    KAUST Repository

    Celik, Abdulkadir

    2016-06-27

    In this paper, we address energy efficient (EE) cooperative spectrum sensing policies for large scale heterogeneous cognitive radio networks (CRNs) which consist of multiple primary channels and large number of secondary users (SUs) with heterogeneous sensing and reporting channel qualities. We approach this issue from macro and micro perspectives. Macro perspective groups SUs into clusters with the objectives: 1) total energy consumption minimization; 2) total throughput maximization; and 3) inter-cluster energy and throughput fairness. We adopt and demonstrate how to solve these using the nondominated sorting genetic algorithm-II. The micro perspective, on the other hand, operates as a sub-procedure on cluster formations decided by the macro perspective. For the micro perspectives, we first propose a procedure to select the cluster head (CH) which yields: 1) the best CH which gives the minimum total multi-hop error rate and 2) the optimal routing paths from SUs to the CH. Exploiting Poisson-Binomial distribution, a novel and generalized K-out-of-N voting rule is developed for heterogeneous CRNs to allow SUs to have different local detection performances. Then, a convex optimization framework is established to minimize the intra-cluster energy cost by jointly obtaining the optimal sensing durations and thresholds of feature detectors for the proposed voting rule. Likewise, instead of a common fixed sample size test, we developed a weighted sample size test for quantized soft decision fusion to obtain a more EE regime under heterogeneity. We have shown that the combination of proposed CH selection and cooperation schemes gives a superior performance in terms of energy efficiency and robustness against reporting error wall.

  14. Cooperative epistemic multi-agent planning for implicit coordination

    DEFF Research Database (Denmark)

    Engesser, Thorsten; Bolander, Thomas; Mattmüller, Robert

    2017-01-01

    framework to include perspective shifts, allowing us to define new notions of sequential and conditional planning with implicit coordination. With these, it is possible to solve planning tasks with joint goals in a decentralized manner without the agents having to negotiate about and commit to a joint...... policy at plan time. First we define the central planning notions and sketch the implementation of a planning system built on those notions. Afterwards we provide some case studies in order to evaluate the planner empirically and to show that the concept is useful for multi-agent systems in practice....

  15. Cooperative Epistemic Multi-Agent Planning With Implicit Coordination

    DEFF Research Database (Denmark)

    Engesser, Thorsten; Bolander, Thomas; Mattmüller, Robert

    2015-01-01

    , meaning coordination is only allowed implicitly by means of the available epistemic actions. While this approach can be fruitfully applied to model reasoning in some simple social situations, we also provide some benchmark applications to show that the concept is useful for multi-agent systems in practice....

  16. Social influence, agent heterogeneity and the emergence of the urban informal sector

    Science.gov (United States)

    García-Díaz, César; Moreno-Monroy, Ana I.

    2012-02-01

    We develop an agent-based computational model in which the urban informal sector acts as a buffer where rural migrants can earn some income while queuing for higher paying modern-sector jobs. In the model, the informal sector emerges as a result of rural-urban migration decisions of heterogeneous agents subject to social influence in the form of neighboring effects of varying strengths. Besides using a multinomial logit choice model that allows for agent idiosyncrasy, explicit agent heterogeneity is introduced in the form of socio-demographic characteristics preferred by modern-sector employers. We find that different combinations of the strength of social influence and the socio-economic composition of the workforce lead to very different urbanization and urban informal sector shares. In particular, moderate levels of social influence and a large proportion of rural inhabitants with preferred socio-demographic characteristics are conducive to a higher urbanization rate and a larger informal sector.

  17. Adaptive Synchronization for Heterogeneous Multi-Agent Systems with Switching Topologies

    Directory of Open Access Journals (Sweden)

    Muhammad Ridho Rosa

    2018-02-01

    Full Text Available This work provides a multi-agent extension of output-feedback model reference adaptive control (MRAC, designed to synchronize a network of heterogeneous uncertain agents. The implementation of this scheme is based on multi-agent matching conditions. The practical advantage of the proposed MRAC is the possibility of handling the case of the unknown dynamics of the agents only by using the output and the control input of its neighbors. In addition, it is reasonable to consider the case when the communication topology is time-varying. In this work, the time-varying communication leads to a switching control structure that depends on the number of the predecessor of the agents. By using the switching control structure to handle the time-varying topologies, we show that synchronization can be achieved. The multi-agent adaptive switching controller is first analyzed, and numerical simulations based on formation control of simplifier quadcopter dynamics are provided.

  18. Transforming stand-alone expert system into a community of cooperating agents

    CERN Document Server

    Jennings, N R; Aarnts, R P; Fuchs, J; Skarek, Paul

    1993-01-01

    Distributed Artificial Intelligence (DAI) systems in which multiple problem solving agents cooperate to achieve a common objective is a rapidly emerging and promising technology. However, as yet, there have been relatively few reported cases of such systems being employed to tackle real-world problems in realistic domains. One of the reasons for this is that DAI researchers have given virtually no consideration to the process of incorporating pre-existing systems into a community of cooperating agents. Yet reuse is a primary consideration for any organisation with a large software base. To redress the balance, this paper reports on an experiment undertaken at the CERN laboratories, in which two pre-existing and standalone expert systems for diagnosing faults in a particle accelerator were transformed into a community of cooperating agents. The experiences and insights gained during this process provide a valuable first step towards satisfying the needs of potential users of DAI technology - identifying the ty...

  19. Design and Profit Allocation in Two-Echelon Heterogeneous Cooperative Logistics Network Optimization

    Directory of Open Access Journals (Sweden)

    Yong Wang

    2018-01-01

    Full Text Available In modern supply chain, logistics companies usually operate individually and optimization researches often concentrate on solving problems related to separate networks. Consequences like the complexity of urban transportation networks and long distance deliveries or pickups and pollution are leading problems to more expenses and more complaints from environment protection organizations. A solution approach to these issues is proposed in this article and consists in the adoption of two-echelon heterogeneous cooperative logistics networks (THCLN. The optimization methodology includes the formation of cooperative coalitions, the reallocation of customers to appropriate logistics facilities, and the determination of the best profit allocation scheme. First, a mixed integer linear programing model is introduced to minimize the total operating cost of nonempty coalitions. Thus, the Genetic Algorithm (GA and the Particle Swarm Optimization (PSO algorithm are hybridized to propose GA-PSO heuristics. GA-PSO is employed to provide good solutions to customer clustering units’ reallocation problem. In addition, a negotiation process is established based on logistics centers as coordinators. The case study of Chongqing city is conducted to verify the feasibility of THCLN in practice. The grand coalition and two heterogeneous subcoalitions are designed, and the collective profit is distributed based on cooperative game theory. The Minimum Cost Remaining Savings (MCRS model is used to determine good allocation schemes and strictly monotonic path principles are considered to evaluate and decide the most appropriate coalition sequence. Comparisons proved the combination of GA-PSO and MCRS better as results are found closest to the core center. Therefore, the proposed approach can be implemented in real world environment, increase the reliability of urban logistics network, and allow decision makers to improve service efficiency.

  20. Moran-evolution of cooperation: From well-mixed to heterogeneous complex networks

    Science.gov (United States)

    Sarkar, Bijan

    2018-05-01

    Configurational arrangement of network architecture and interaction character of individuals are two most influential factors on the mechanisms underlying the evolutionary outcome of cooperation, which is explained by the well-established framework of evolutionary game theory. In the current study, not only qualitatively but also quantitatively, we measure Moran-evolution of cooperation to support an analytical agreement based on the consequences of the replicator equation in a finite population. The validity of the measurement has been double-checked in the well-mixed network by the Langevin stochastic differential equation and the Gillespie-algorithmic version of Moran-evolution, while in a structured network, the measurement of accuracy is verified by the standard numerical simulation. Considering the Birth-Death and Death-Birth updating rules through diffusion of individuals, the investigation is carried out in the wide range of game environments those relate to the various social dilemmas where we are able to draw a new rigorous mathematical track to tackle the heterogeneity of complex networks. The set of modified criteria reveals the exact fact about the emergence and maintenance of cooperation in the structured population. We find that in general, nature promotes the environment of coexistent traits.

  1. Cooperative mobile agents search using beehive partitioned structure and Tabu Random search algorithm

    Science.gov (United States)

    Ramazani, Saba; Jackson, Delvin L.; Selmic, Rastko R.

    2013-05-01

    In search and surveillance operations, deploying a team of mobile agents provides a robust solution that has multiple advantages over using a single agent in efficiency and minimizing exploration time. This paper addresses the challenge of identifying a target in a given environment when using a team of mobile agents by proposing a novel method of mapping and movement of agent teams in a cooperative manner. The approach consists of two parts. First, the region is partitioned into a hexagonal beehive structure in order to provide equidistant movements in every direction and to allow for more natural and flexible environment mapping. Additionally, in search environments that are partitioned into hexagons, mobile agents have an efficient travel path while performing searches due to this partitioning approach. Second, we use a team of mobile agents that move in a cooperative manner and utilize the Tabu Random algorithm to search for the target. Due to the ever-increasing use of robotics and Unmanned Aerial Vehicle (UAV) platforms, the field of cooperative multi-agent search has developed many applications recently that would benefit from the use of the approach presented in this work, including: search and rescue operations, surveillance, data collection, and border patrol. In this paper, the increased efficiency of the Tabu Random Search algorithm method in combination with hexagonal partitioning is simulated, analyzed, and advantages of this approach are presented and discussed.

  2. Decentralized Planning for Autonomous Agents Cooperating in Complex Missions

    Science.gov (United States)

    2010-09-01

    is a " lawn mower " search path. The world is divided into N, rectangles, and each agent traverses its own rectangle by sweeping back and forth in a...mission. Furthermore, the random walk never found more than three targets for the 50 missions simulated, as seen in Figure 5-7. The lawn mower search...that both the random walk and the lawn mower search seem to find targets at a linear rate with respect to time, whereas the other four strategies are

  3. Modelling cooperation of industrial robots as multi-agent systems

    Science.gov (United States)

    Hryniewicz, P.; Banas, W.; Foit, K.; Gwiazda, A.; Sekala, A.

    2017-08-01

    Nowadays, more and more often in a cell is more than one robot, there is also a dual arm robots, because of this cooperation of two robots in the same space becomes more and more important. Programming robotic cell consisting of two or more robots are currently performed separately for each element of the robot and the cell. It is performed only synchronization programs, but no robot movements. In such situations often placed industrial robots so they do not have common space so the robots are operated separately. When industrial robots are a common space this space can occupy only one robot the other one must be outside the common space. It is very difficult to find applications where two robots are in the same workspace. It was tested but one robot did not do of movement when moving the second and waited for permission to move from the second when it sent a permit - stop the move. Such programs are very difficult and require a lot of experience from the programmer and must be tested separately at the beginning and then very slowly under control. Ideally, the operator takes care of exactly one robot during the test and it is very important to take special care.

  4. Effects of Heterogeneity in Residential Preferences on an Agent-Based Model of Urban Sprawl

    Directory of Open Access Journals (Sweden)

    Daniel G. Brown

    2006-06-01

    Full Text Available The ability of agent-based models (ABMs to represent heterogeneity in the characteristics and behaviors of actors enables analyses about the implications of this heterogeneity for system behavior. The importance of heterogeneity in the specification of ABMs, however, creates new demands for empirical support. An earlier analysis of a survey of residential preferences within southeastern Michigan revealed seven groups of residents with similar preferences on similar characteristics of location. In this paper, we present an ABM that represents the process of residential development within an urban system and run it for a hypothetical pattern of environmental variation. Residential locations are selected by residential agents, who evaluate locations on the basis of preference for nearness to urban services, including jobs, aesthetic quality of the landscape, and their similarity to their neighbors. We populate our ABM with a population of residential preferences drawn from the survey results in five different ways: (1 preferences drawn at random; (2 equal preferences based on the mean from the entire survey sample; (3 preferences drawn from a single distribution, whose mean and standard deviation are derived from the survey sample; (4 equal preferences within each of seven groups, based on the group means; and (5 preferences drawn from distributions for each of seven groups, defined by group means and standard deviations. Model sensitivity analysis, based on multiple runs of our model under each case, revealed that adding heterogeneity to agents has a significant effect on model outcomes, measured by aggregate patterns of development sprawl and clustering.

  5. Improved success of sparse matrix protein crystallization screening with heterogeneous nucleating agents.

    Directory of Open Access Journals (Sweden)

    Anil S Thakur

    2007-10-01

    Full Text Available Crystallization is a major bottleneck in the process of macromolecular structure determination by X-ray crystallography. Successful crystallization requires the formation of nuclei and their subsequent growth to crystals of suitable size. Crystal growth generally occurs spontaneously in a supersaturated solution as a result of homogenous nucleation. However, in a typical sparse matrix screening experiment, precipitant and protein concentration are not sampled extensively, and supersaturation conditions suitable for nucleation are often missed.We tested the effect of nine potential heterogenous nucleating agents on crystallization of ten test proteins in a sparse matrix screen. Several nucleating agents induced crystal formation under conditions where no crystallization occurred in the absence of the nucleating agent. Four nucleating agents: dried seaweed; horse hair; cellulose and hydroxyapatite, had a considerable overall positive effect on crystallization success. This effect was further enhanced when these nucleating agents were used in combination with each other.Our results suggest that the addition of heterogeneous nucleating agents increases the chances of crystal formation when using sparse matrix screens.

  6. Assessment of Cooperative and Heterogeneous Indoor Localization Algorithms with Real Radio Devices

    DEFF Research Database (Denmark)

    Nielsen, Jimmy Jessen; Noureddine, Hadi; Amiot, Nicolas

    2014-01-01

    In this paper we present results of real-life local- ization experiments performed in an unprecedented cooperative and heterogeneous wireless context. The experiments covered measurements of different radio devices packed together on a trolley, emulating a multi-standard Mobile Terminal (MT) along...... representative trajectories in a crowded office environment. Among all the radio access technologies involved in this campaign (including LTE, WiFi...), the focus is herein put mostly on Impulse Radio - Ultra Wideband (IR-UWB) and ZigBee sub-systems, which are enabled with peer-to-peer ranging capabilities based...... on Time of Arrival (ToA) estimation and Received Signal Strength (RSS) measurements respectively. Single-link model parameters are preliminarily drawn and discussed. In comparison with existing similar campaigns, new algorithms are also applied to the measurement data, showing the interest of advanced de...

  7. The transmission of sustainable harvesting norms when agents are conditionally cooperative

    NARCIS (Netherlands)

    Richter, Andries; Grasman, J.

    2013-01-01

    Experimental and observational studies have highlighted the importance of agents being conditionally cooperative when facing a social dilemma. We formalize this mechanism in a theoretical model that portrays a small community having joint access to a common pool resource. The diffusion of norms of

  8. 77 FR 44582 - Applications To Serve as Accountability Agents in the Asia Pacific Economic Cooperation (APEC...

    Science.gov (United States)

    2012-07-30

    ... Accountability Agent for U.S.-based companies that are subject to Federal Trade Commission jurisdiction as part..., Malaysia, Mexico, New Zealand, Papua New Guinea, Peru, Philippines, Russia, Singapore, Chinese Taipei... CPEA creates a framework for regional cooperation in the enforcement of privacy laws. In the case of...

  9. Promotion of cooperation induced by heterogeneity of both investment and payoff allocation in spatial public goods game

    Science.gov (United States)

    Fan, Ruguo; Zhang, Yingqing; Luo, Ming; Zhang, Hongjuan

    2017-01-01

    Heterogeneity has attracted mounting attention across multiple disciplines and is confirmed to be a greater promoter of cooperation. It is often the case that the heterogeneity always exists in investment and payoff allocation concurrently instead of separately. In addition, the factors that affect heterogeneous investment and payoff allocation are various. Inspired by this, this paper extends the previous models by incorporating heterogeneous investment and payoff allocation into the typical PGG model to further investigate the incentive mechanisms of cooperative behavior. In order to better understand the model, three different feedback mechanisms, namely the wealth-preference mechanism, the social-self-preference mechanism, and the mixed-preference mechanism, are addressed. The former two mechanisms correspond to the case of single factor and the latter corresponds to the case of double factors. The numerical simulations indicate that feedback mechanism by bridging the connections between the investment and the payoff allocation can reduce the free-rider problem. Furthermore, it is found that the cooperative frequency and average payoff perform better in the case of the mixed-preference mechanism where players will not only take previous payoff feedback as well as current investment but also their social status into their game decision-making process. In addition, full cooperation and profitability over all players can be promoted by means of increasing r or reducing α. At last, compared with another two classic networks, the extent of cooperation is promoted under the structures of the BA scale free networks.

  10. Emergence of cooperation in phenotypically heterogeneous populations: a replicator dynamics analysis

    International Nuclear Information System (INIS)

    Barreira da Silva Rocha, A; Escobedo, R; Laruelle, A

    2015-01-01

    The emergence of cooperation is analyzed in heterogeneous populations where two kinds of individuals exist according to their phenotypic appearance. Phenotype recognition is assumed for all individuals: individuals are able to identify the type of every other individual, but fail to recognize their own type. Individuals thus behave under partial information conditions. The interactions between individuals are described by the snowdrift game, where individuals can either cooperate or defect. The evolution of such populations is studied in the framework of evolutionary game theory by means of the replicator dynamics. Overlapping generations are considered, so the replicator equations are formulated in discrete-time form. The stability analysis of the dynamical system is carried out and a detailed description of the behavior of trajectories starting from the interior of the state-space is given. We find that the four monomorphic states are unstable and that a polymorphic state exists which is a global attractor for non-degenerate initial states of the population. The result for the discrete-time replicator coincides with the one of the continuous case. (paper)

  11. With Us or Against Us: Simulated Social Touch by Virtual Agents in a Cooperative or Competitive Setting

    NARCIS (Netherlands)

    Huisman, Gijs; Kolkmeier, Jan; Kolkmeier, Jan; Heylen, Dirk K.J.; Bickmore, Timothy; Marsella, Stacy; Sidner, Candance

    In this paper we examine how simulated social touch by a virtual agent in a cooperative or competitive augmented reality game influences the perceived trustworthiness, warmth and politeness of the agent. Before and after the game, participants interact with two agents whereby one agent touches the

  12. A cooperative game-theoretic framework for negotiating marine spatial allocation agreements among heterogeneous players.

    Science.gov (United States)

    Kyriazi, Zacharoula; Lejano, Raul; Maes, Frank; Degraer, Steven

    2017-02-01

    Marine spatial allocation has become, in recent decades, a political flashpoint, fuelled by political power struggles, as well as the continuously increasing demand for marine space by both traditional and emerging marine uses. To effectively address this issue, we develop a decision-making procedure, that facilitates the distribution of disputed areas of specific size among heterogeneous players in a transparent and ethical way, while considering coalitional formations through coexistence. To do this, we model players' alternative strategies and payoffs within a cooperative game-theoretic framework. Depending on whether transferable utility (TU) or non-transferable utility (NTU) is the more appropriate assumption, we illustrate the use of the TU Shapley value and the Lejano's fixed point NTU Shapley value to solve for the ideal allocations. The applicability and effectiveness of the process has been tested in a case study area, the Dogger Bank Special Area of Conservation in the North Sea, which involves three totally or partially conflicting activities, i.e. fishing, nature conservation and wind farm development. The findings demonstrate that the process is capable of providing a unique, fair and equitable division of space Finally, among the two solution concepts proposed the fixed point NTU Shapley value manages to better address the heterogeneity of the players and thus to provide a more socially acceptable allocation that favours the weaker player, while demonstrating the importance of the monetary valuation attributed by each use to the area. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Effects of competition and cooperation interaction between agents on networks in the presence of a market capacity

    Science.gov (United States)

    Sonubi, A.; Arcagni, A.; Stefani, S.; Ausloos, M.

    2016-08-01

    A network effect is introduced taking into account competition, cooperation, and mixed-type interaction among agents along a generalized Verhulst-Lotka-Volterra model. It is also argued that the presence of a market capacity undoubtedly enforces a definite limit on the agent's size growth. The state stability of triadic agents, i.e., the most basic network plaquette, is investigated analytically for possible scenarios, through a fixed-point analysis. It is discovered that: (i) market demand is only satisfied for full competition when one agent monopolizes the market; (ii) growth of agent size is encouraged in full cooperation; (iii) collaboration among agents to compete against one single agent may result in the disappearance of this single agent out of the market; and (iv) cooperating with two rivals may become a growth strategy for an intelligent agent.

  14. Effects of competition and cooperation interaction between agents on networks in the presence of a market capacity.

    Science.gov (United States)

    Sonubi, A; Arcagni, A; Stefani, S; Ausloos, M

    2016-08-01

    A network effect is introduced taking into account competition, cooperation, and mixed-type interaction among agents along a generalized Verhulst-Lotka-Volterra model. It is also argued that the presence of a market capacity undoubtedly enforces a definite limit on the agent's size growth. The state stability of triadic agents, i.e., the most basic network plaquette, is investigated analytically for possible scenarios, through a fixed-point analysis. It is discovered that: (i) market demand is only satisfied for full competition when one agent monopolizes the market; (ii) growth of agent size is encouraged in full cooperation; (iii) collaboration among agents to compete against one single agent may result in the disappearance of this single agent out of the market; and (iv) cooperating with two rivals may become a growth strategy for an intelligent agent.

  15. Two-agent cooperative search using game models with endurance-time constraints

    Science.gov (United States)

    Sujit, P. B.; Ghose, Debasish

    2010-07-01

    In this article, the problem of two Unmanned Aerial Vehicles (UAVs) cooperatively searching an unknown region is addressed. The search region is discretized into hexagonal cells and each cell is assumed to possess an uncertainty value. The UAVs have to cooperatively search these cells taking limited endurance, sensor and communication range constraints into account. Due to limited endurance, the UAVs need to return to the base station for refuelling and also need to select a base station when multiple base stations are present. This article proposes a route planning algorithm that takes endurance time constraints into account and uses game theoretical strategies to reduce the uncertainty. The route planning algorithm selects only those cells that ensure the agent will return to any one of the available bases. A set of paths are formed using these cells which the game theoretical strategies use to select a path that yields maximum uncertainty reduction. We explore non-cooperative Nash, cooperative and security strategies from game theory to enhance the search effectiveness. Monte-Carlo simulations are carried out which show the superiority of the game theoretical strategies over greedy strategy for different look ahead step length paths. Within the game theoretical strategies, non-cooperative Nash and cooperative strategy perform similarly in an ideal case, but Nash strategy performs better than the cooperative strategy when the perceived information is different. We also propose a heuristic based on partitioning of the search space into sectors to reduce computational overhead without performance degradation.

  16. Behavioural breaks in the heterogeneous agent model: The impact of herding, overconfidence, and market sentiment

    Czech Academy of Sciences Publication Activity Database

    Kukačka, Jiří; Baruník, Jozef

    2013-01-01

    Roč. 392, č. 23 (2013), s. 5920-5938 ISSN 0378-4371 R&D Projects: GA ČR GA402/09/0965 Institutional support: RVO:67985556 Keywords : Heterogeneous agent model * Behavioural finance * Herding * Overconfidence * Market sentiment * Stock market crash Subject RIV: AH - Economics Impact factor: 1.722, year: 2013 http://library.utia.cas.cz/separaty/2013/E/barunik-0395344.pdf

  17. Automation of multi-agent control for complex dynamic systems in heterogeneous computational network

    Science.gov (United States)

    Oparin, Gennady; Feoktistov, Alexander; Bogdanova, Vera; Sidorov, Ivan

    2017-01-01

    The rapid progress of high-performance computing entails new challenges related to solving large scientific problems for various subject domains in a heterogeneous distributed computing environment (e.g., a network, Grid system, or Cloud infrastructure). The specialists in the field of parallel and distributed computing give the special attention to a scalability of applications for problem solving. An effective management of the scalable application in the heterogeneous distributed computing environment is still a non-trivial issue. Control systems that operate in networks, especially relate to this issue. We propose a new approach to the multi-agent management for the scalable applications in the heterogeneous computational network. The fundamentals of our approach are the integrated use of conceptual programming, simulation modeling, network monitoring, multi-agent management, and service-oriented programming. We developed a special framework for an automation of the problem solving. Advantages of the proposed approach are demonstrated on the parametric synthesis example of the static linear regulator for complex dynamic systems. Benefits of the scalable application for solving this problem include automation of the multi-agent control for the systems in a parallel mode with various degrees of its detailed elaboration.

  18. A few bad apples: a model of disease influenced agent behaviour in a heterogeneous contact environment.

    Directory of Open Access Journals (Sweden)

    Jessica Enright

    Full Text Available For diseases that infect humans or livestock, transmission dynamics are at least partially dependent on human activity and therefore human behaviour. However, the impact of human behaviour on disease transmission is relatively understudied, especially in the context of heterogeneous contact structures such as described by a social network. Here, we use a strategic game, coupled with a simple disease model, to investigate how strategic agent choices impact the spread of disease over a contact network. Using beliefs that are based on disease status and that build up over time, agents choose actions that stochastically determine disease spread on the network. An agent's disease status is therefore a function of both his own and his neighbours actions. The effect of disease on agents is modelled by a heterogeneous payoff structure. We find that the combination of network shape and distribution of payoffs has a non-trivial impact on disease prevalence, even if the mean payoff remains the same. An important scenario occurs when a small percentage (called noncooperators have little incentive to avoid disease. For diseases that are easily acquired when taking a risk, then even when good behavior can lead to disease eradication, a small increase in the percentage of noncooperators (less than 5% can yield a large (up to 25% increase in prevalence.

  19. Patterns of cooperation: fairness and coordination in networks of interacting agents

    Science.gov (United States)

    Do, Anne-Ly; Rudolf, Lars; Gross, Thilo

    2010-06-01

    We study the self-assembly of a complex network of collaborations among self-interested agents. The agents can maintain different levels of cooperation with different partners. Further, they continuously, selectively and independently adapt the amount of resources allocated to each of their collaborations in order to maximize the obtained payoff. We show analytically that the system approaches a state in which the agents make identical investments, and links produce identical benefits. Despite this high degree of social coordination, some agents manage to secure privileged topological positions in the network, enabling them to extract high payoffs. Our analytical investigations provide a rationale for the emergence of unidirectional non-reciprocal collaborations and different responses to the withdrawal of a partner from an interaction that have been reported in the psychological literature.

  20. The Evolution of Cooperation in Managed Groundwater Systems: An Agent-Based Modelling Approach

    Science.gov (United States)

    Castilla Rho, J. C.; Mariethoz, G.; Rojas, R. F.; Andersen, M. S.; Kelly, B. F.; Holley, C.

    2014-12-01

    Human interactions with groundwater systems often exhibit complex features that hinder the sustainable management of the resource. This leads to costly and persistent conflicts over groundwater at the catchment scale. One possible way to address these conflicts is by gaining a better understanding of how social and groundwater dynamics coevolve using agent-based models (ABM). Such models allow exploring 'bottom-up' solutions (i.e., self-organised governance systems), where the behaviour of individual agents (e.g., farmers) results in the emergence of mutual cooperation among groundwater users. There is significant empirical evidence indicating that this kind of 'bottom-up' approach may lead to more enduring and sustainable outcomes, compared to conventional 'top-down' strategies such as centralized control and water right schemes (Ostrom 1990). New modelling tools are needed to study these concepts systematically and efficiently. Our model uses a conceptual framework to study cooperation and the emergence of social norms as initially proposed by Axelrod (1986), which we adapted to groundwater management. We developed an ABM that integrates social mechanisms and the physics of subsurface flow. The model explicitly represents feedback between groundwater conditions and social dynamics, capturing the spatial structure of these interactions and the potential effects on cooperation levels in an agricultural setting. Using this model, we investigate a series of mechanisms that may trigger norms supporting cooperative strategies, which can be sustained and become stable over time. For example, farmers in a self-monitoring community can be more efficient at achieving the objective of sustainable groundwater use than government-imposed regulation. Our coupled model thus offers a platform for testing new schemes promoting cooperation and improved resource use, which can be used as a basis for policy design. Importantly, we hope to raise awareness of agent-based modelling as

  1. MR brain scan tissues and structures segmentation: local cooperative Markovian agents and Bayesian formulation

    International Nuclear Information System (INIS)

    Scherrer, B.

    2008-12-01

    Accurate magnetic resonance brain scan segmentation is critical in a number of clinical and neuroscience applications. This task is challenging due to artifacts, low contrast between tissues and inter-individual variability that inhibit the introduction of a priori knowledge. In this thesis, we propose a new MR brain scan segmentation approach. Unique features of this approach include (1) the coupling of tissue segmentation, structure segmentation and prior knowledge construction, and (2) the consideration of local image properties. Locality is modeled through a multi-agent framework: agents are distributed into the volume and perform a local Markovian segmentation. As an initial approach (LOCUS, Local Cooperative Unified Segmentation), intuitive cooperation and coupling mechanisms are proposed to ensure the consistency of local models. Structures are segmented via the introduction of spatial localization constraints based on fuzzy spatial relations between structures. In a second approach, (LOCUS-B, LOCUS in a Bayesian framework) we consider the introduction of a statistical atlas to describe structures. The problem is reformulated in a Bayesian framework, allowing a statistical formalization of coupling and cooperation. Tissue segmentation, local model regularization, structure segmentation and local affine atlas registration are then coupled in an EM framework and mutually improve. The evaluation on simulated and real images shows good results, and in particular, a robustness to non-uniformity and noise with low computational cost. Local distributed and cooperative MRF models then appear as a powerful and promising approach for medical image segmentation. (author)

  2. Adaptive Load Balancing of Parallel Applications with Multi-Agent Reinforcement Learning on Heterogeneous Systems

    Directory of Open Access Journals (Sweden)

    Johan Parent

    2004-01-01

    Full Text Available We report on the improvements that can be achieved by applying machine learning techniques, in particular reinforcement learning, for the dynamic load balancing of parallel applications. The applications being considered in this paper are coarse grain data intensive applications. Such applications put high pressure on the interconnect of the hardware. Synchronization and load balancing in complex, heterogeneous networks need fast, flexible, adaptive load balancing algorithms. Viewing a parallel application as a one-state coordination game in the framework of multi-agent reinforcement learning, and by using a recently introduced multi-agent exploration technique, we are able to improve upon the classic job farming approach. The improvements are achieved with limited computation and communication overhead.

  3. A Heterogeneous Agent Model of Asspet Price with Three Time Delays

    Directory of Open Access Journals (Sweden)

    Akio Matsumoto

    2016-09-01

    Full Text Available This paper considers a continuous-time heterogeneous agent model ofa ...nancial market with one risky asset, two types of agents (i.e., thefundamentalists and the chartists, and three time delays. The chartistdemand is determined through a nonlinear function of the di¤erence be-tween the current price and a weighted moving average of the delayedprices whereas the fundamentalist demand is governed by the di¤erencebetween the current price and the fundamental value. The asset price dy-namics is described by a nonlinear delay di¤erential equation. Two mainresults are analytically and numerically shown:(i the delay destabilizes the market price and generates cyclic oscillationsaround the equilibrium;(ii under multiple delays, stability loss and gain repeatedly occurs as alength of the delay increases.

  4. A multi-agent conversational system with heterogeneous data sources access

    KAUST Repository

    Eisman, Eduardo M.

    2016-01-28

    In many of the problems that can be found nowadays, information is scattered across different heterogeneous data sources. Most of the natural language interfaces just focus on a very specific part of the problem (e.g. an interface to a relational database, or an interface to an ontology). However, from the point of view of users, it does not matter where the information is stored, they just want to get the knowledge in an integrated, transparent, efficient, effective, and pleasant way. To solve this problem, this article proposes a generic multi-agent conversational architecture that follows the divide and conquer philosophy and considers two different types of agents. Expert agents are specialized in accessing different knowledge sources, and decision agents coordinate them to provide a coherent final answer to the user. This architecture has been used to design and implement SmartSeller, a specific system which includes a Virtual Assistant to answer general questions and a Bookseller to query a book database. A deep analysis regarding other relevant systems has demonstrated that our proposal provides several improvements at some key features presented along the paper.

  5. A multi-agent conversational system with heterogeneous data sources access

    KAUST Repository

    Eisman, Eduardo M.; Navarro, Marí a; Castro, Juan Luis

    2016-01-01

    In many of the problems that can be found nowadays, information is scattered across different heterogeneous data sources. Most of the natural language interfaces just focus on a very specific part of the problem (e.g. an interface to a relational database, or an interface to an ontology). However, from the point of view of users, it does not matter where the information is stored, they just want to get the knowledge in an integrated, transparent, efficient, effective, and pleasant way. To solve this problem, this article proposes a generic multi-agent conversational architecture that follows the divide and conquer philosophy and considers two different types of agents. Expert agents are specialized in accessing different knowledge sources, and decision agents coordinate them to provide a coherent final answer to the user. This architecture has been used to design and implement SmartSeller, a specific system which includes a Virtual Assistant to answer general questions and a Bookseller to query a book database. A deep analysis regarding other relevant systems has demonstrated that our proposal provides several improvements at some key features presented along the paper.

  6. Cooperative biological effects between ionizing radiation and other physical and chemical agents.

    Science.gov (United States)

    Manti, Lorenzo; D'Arco, Annalisa

    2010-01-01

    Exposure to ionizing radiation (IR), at environmentally and therapeutically relevant doses or as a result of diagnostics or accidents, causes cyto- and genotoxic damage. However, exposure to IR alone is a rare event as it occurs in spatial and temporal combination with several physico-chemical agents. Some of these are of known noxiousness, as is the case with chemical compounds at high dose, hence additive/synergistic effects can be expected or have been demonstrated. Conversely, the cellular toxicity of other agents, such as non-ionizing electromagnetic fields (EMFs), is only presumed and their short- and long-term cooperation on IR-induced damage remains undetermined. In this review, we shall examine evidence in support of the interplay between spatially and/or temporally related environmentally relevant stressors. In vitro or animal-based studies as well as epidemiological surveys have generally examined the combined action of no more than a couple of known or potentially DNA-damaging agents. Moreover, most existing research mainly focused on short-term effects of combined exposures. Hence, it is important that quantitative research addresses the issue of the possible cooperation between chronic exposure to environmental trace contaminants and exposure to EMFs, examining not only the modulation of damage acutely induced by IR but also long-term genome stability. 2010 Elsevier B.V. All rights reserved.

  7. Characterization of image heterogeneity using 2D Minkowski functionals increases the sensitivity of detection of a targeted MRI contrast agent.

    Science.gov (United States)

    Canuto, Holly C; McLachlan, Charles; Kettunen, Mikko I; Velic, Marko; Krishnan, Anant S; Neves, Andre' A; de Backer, Maaike; Hu, D-E; Hobson, Michael P; Brindle, Kevin M

    2009-05-01

    A targeted Gd(3+)-based contrast agent has been developed that detects tumor cell death by binding to the phosphatidylserine (PS) exposed on the plasma membrane of dying cells. Although this agent has been used to detect tumor cell death in vivo, the differences in signal intensity between treated and untreated tumors was relatively small. As cell death is often spatially heterogeneous within tumors, we investigated whether an image analysis technique that parameterizes heterogeneity could be used to increase the sensitivity of detection of this targeted contrast agent. Two-dimensional (2D) Minkowski functionals (MFs) provided an automated and reliable method for parameterization of image heterogeneity, which does not require prior assumptions about the number of regions or features in the image, and were shown to increase the sensitivity of detection of the contrast agent as compared to simple signal intensity analysis. (c) 2009 Wiley-Liss, Inc.

  8. Colorectal liver metastases: contrast agent diffusion coefficient for quantification of contrast enhancement heterogeneity at MR imaging.

    Science.gov (United States)

    Jia, Guang; O'Dell, Craig; Heverhagen, Johannes T; Yang, Xiangyu; Liang, Jiachao; Jacko, Richard V; Sammet, Steffen; Pellas, Theodore; Cole, Patricia; Knopp, Michael V

    2008-09-01

    To describe and determine the reproducibility of a simplified model to quantitatively measure heterogeneous intralesion contrast agent diffusion in colorectal liver metastases. This HIPAA-compliant retrospective study received institutional review board approval, and written informed consent was obtained from 14 patients (mean age, 61 years +/- 9 [standard deviation]; range, 41-78 years), including 10 men (mean age, 65 years +/- 8; range, 47-78 years) and four women (mean age, 54 years +/- 9; range, 41-59 years), with colorectal liver metastases. Magnetic resonance (MR) imaging was performed twice (first baseline MR image [B(1)] and second baseline MR image [B(2)]) in a single target lesion prior to therapy. Dynamic contrast material-enhanced MR imaging was performed by using a saturation-recovery fast gradient-echo sequence. A simplified contrast agent diffusion model was proposed, and a contrast agent diffusion coefficient (CDC) was calculated. The reproducibility of the CDC measurement was evaluated by using the Bland-Altman plot and a linear regression model. The mean CDC was 0.22 mm(2)/sec (range, 0.01-0.73 mm(2)/sec) on B(1) and 0.24 mm(2)/sec (range, 0.01-0.71 mm(2)/sec) on B(2), with an intraclass correlation coefficient of 0.91 (P < .0001). Bland-Altman plot showed good agreement, with a mean difference in measurement pairs of 0.017 mm(2)/sec +/- 0.096. The slope from the linear regression model was 0.89 (95% confidence interval: 0.63, 1.15) and the intercept was 0.01 (95% confidence interval: -0.08, 0.09). The CDC enables a quantitative description of contrast enhancement heterogeneity in lesions. Given the high reproducibility of the CDC metric, CDC appears promising for further qualification as an imaging biomarker of change measurement in response assessment. http://radiology.rsnajnls.org/cgi/content/full/248/3/901/DC1. RSNA, 2008

  9. A framework for service enterprise workflow simulation with multi-agents cooperation

    Science.gov (United States)

    Tan, Wenan; Xu, Wei; Yang, Fujun; Xu, Lida; Jiang, Chuanqun

    2013-11-01

    Process dynamic modelling for service business is the key technique for Service-Oriented information systems and service business management, and the workflow model of business processes is the core part of service systems. Service business workflow simulation is the prevalent approach to be used for analysis of service business process dynamically. Generic method for service business workflow simulation is based on the discrete event queuing theory, which is lack of flexibility and scalability. In this paper, we propose a service workflow-oriented framework for the process simulation of service businesses using multi-agent cooperation to address the above issues. Social rationality of agent is introduced into the proposed framework. Adopting rationality as one social factor for decision-making strategies, a flexible scheduling for activity instances has been implemented. A system prototype has been developed to validate the proposed simulation framework through a business case study.

  10. FY1995 distributed control of man-machine cooperative multi agent systems; 1995 nendo ningen kyochogata multi agent kikai system no jiritsu seigyo

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    In the near future, distributed autonomous systems will be practical in many situations, e.g., interactive production systems, hazardous environments, nursing homes, and individual houses. The agents which consist of the distributed system must not give damages to human being and should be working economically. In this project man-machine cooperative multi agent systems are studied in many kind of respects, and basic design technology, basic control technique are developed by establishing fundamental theories and by constructing experimental systems. In this project theoretical and experimental studies are conducted in the following sub-projects: (1) Distributed cooperative control in multi agent type actuation systems (2) Control of non-holonomic systems (3) Man-machine Cooperative systems (4) Robot systems learning human skills (5) Robust force control of constrained systems In each sub-project cooperative nature between machine agent systems and human being, interference between artificial multi agents and environment and new function emergence in coordination of the multi agents and the environment, robust force control against for the environments, control methods for non-holonomic systems, robot systems which can mimic and learn human skills were studied. In each sub-project, some problems were hi-lighted and solutions for the problems have been given based on construction of experimental systems. (NEDO)

  11. Grouped to Achieve: Are There Benefits to Assigning Students to Heterogeneous Cooperative Learning Groups Based on Pre-Test Scores?

    Science.gov (United States)

    Werth, Arman Karl

    Cooperative learning has been one of the most widely used instructional practices around the world since the early 1980's. Small learning groups have been in existence since the beginning of the human race. These groups have grown in their variance and complexity overtime. Classrooms are getting more diverse every year and instructors need a way to take advantage of this diversity to improve learning. The purpose of this study was to see if heterogeneous cooperative learning groups based on student achievement can be used as a differentiated instructional strategy to increase students' ability to demonstrate knowledge of science concepts and ability to do engineering design. This study includes two different groups made up of two different middle school science classrooms of 25-30 students. These students were given an engineering design problem to solve within cooperative learning groups. One class was put into heterogeneous cooperative learning groups based on student's pre-test scores. The other class was grouped based on random assignment. The study measured the difference between each class's pre-post gains, student's responses to a group interaction form and interview questions addressing their perceptions of the makeup of their groups. The findings of the study were that there was no significant difference between learning gains for the treatment and comparison groups. There was a significant difference between the treatment and comparison groups in student perceptions of their group's ability to stay on task and manage their time efficiently. Both the comparison and treatment groups had a positive perception of the composition of their cooperative learning groups.

  12. Cognitive strategies take advantage of the cooperative potential of heterogeneous networks

    International Nuclear Information System (INIS)

    Vukov, Jeromos; Santos, Francisco C; Pacheco, Jorge M

    2012-01-01

    Understanding the emergence and maintenance of cooperation is one of the most challenging topics of our time. Evolutionary game theory offers a very flexible framework within which to address this challenge. Here we use the prisoner's dilemma game to investigate the performance of individuals who are capable of adopting reactive strategies in communities structurally organized by means of Barabási-Albert scale-free networks. We find that basic cognitive abilities, such as the capability to distinguish their partners and act according to their previous actions, enable cooperation to thrive. This result is particularly significant whenever fear is the leading social tension, as this fosters retaliation, thus enforcing and sustaining cooperation. Being able to simultaneously reward fellow cooperators and punish defectors proves instrumental in achieving cooperation and the welfare of the community. As a result, central individuals can successfully lead the community and turn defective players into cooperative ones. Finally, even when participation costs—known to be detrimental to cooperation in scale-free networks—are explicitly included, we find that basic cognitive abilities have enough potential to help cooperation to prevail. (paper)

  13. International Migration with Heterogeneous Agents: Theory and Evidence for Germany, 1967-2009

    DEFF Research Database (Denmark)

    Brücker, Herbert; Schröder, Philipp

    2012-01-01

    Temporary migration, though empirically relevant, is often ignored in formal models. This paper proposes a migration model with heterogeneous agents and persistent cross country income differentials that features temporary migration. In equilibrium there exists a positive relation between the stock...... of migrants and the income differential, while the net migration flow becomes zero. Consequently, existing empirical migration models, estimating net migration flows, instead of stocks, may be misspecified. This suspicion appears to be confirmed by our investigation of the cointegration relationships...... of German migration stocks and flows since 1967. We find that (i) panel-unit root tests reject the hypothesis that migration flows and the explanatory variables are integrated of the same order, while migration stocks and the explanatory variables are all I(1) variables, and (ii) the hypothesis...

  14. 77 FR 61786 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Heterogeneous...

    Science.gov (United States)

    2012-10-11

    ... Production Act of 1993--Heterogeneous System Architecture Foundation Notice is hereby given that, on August..., 15 U.S.C. 4301 et seq. (``the Act''), Heterogeneous System Architecture Foundation (``HSA Foundation... limited to, building and promoting the common business interests of the semiconductor industry by...

  15. Multi-Objective Clustering Optimization for Multi-Channel Cooperative Spectrum Sensing in Heterogeneous Green CRNs

    KAUST Repository

    Celik, Abdulkadir; Kamal, Ahmed E.

    2016-01-01

    ) with heterogeneous sensing and reporting channel qualities. We approach this issue from macro and micro perspectives. Macro perspective groups SUs into clusters with the objectives: 1) total energy consumption minimization; 2) total throughput maximization; and 3

  16. Multi-Agent Decision Support Tool to Enable Interoperability among Heterogeneous Energy Systems

    Directory of Open Access Journals (Sweden)

    Brígida Teixeira

    2018-02-01

    Full Text Available Worldwide electricity markets are undergoing a major restructuring process. One of the main reasons for the ongoing changes is to enable the adaptation of current market models to the new paradigm that arises from the large-scale integration of distributed generation sources. In order to deal with the unpredictability caused by the intermittent nature of the distributed generation and the large number of variables that contribute to the energy sector balance, it is extremely important to use simulation systems that are capable of dealing with the required complexity. This paper presents the Tools Control Center (TOOCC, a framework that allows the interoperability between heterogeneous energy and power simulation systems through the use of ontologies, allowing the simulation of scenarios with a high degree of complexity, through the cooperation of the individual capacities of each system. A case study based on real data is presented in order to demonstrate the interoperability capabilities of TOOCC. The simulation considers the energy management of a microgrid of a real university campus, from the perspective of the network manager and also of its consumers/producers, in a projection for a typical day of the winter of 2050.

  17. Tumour cell heterogeneity maintained by cooperating subclones in Wnt-driven mammary cancers.

    Science.gov (United States)

    Cleary, Allison S; Leonard, Travis L; Gestl, Shelley A; Gunther, Edward J

    2014-04-03

    Cancer genome sequencing studies indicate that a single breast cancer typically harbours multiple genetically distinct subclones. As carcinogenesis involves a breakdown in the cell-cell cooperation that normally maintains epithelial tissue architecture, individual subclones within a malignant microenvironment are commonly depicted as self-interested competitors. Alternatively, breast cancer subclones might interact cooperatively to gain a selective growth advantage in some cases. Although interclonal cooperation has been shown to drive tumorigenesis in fruitfly models, definitive evidence for functional cooperation between epithelial tumour cell subclones in mammals is lacking. Here we use mouse models of breast cancer to show that interclonal cooperation can be essential for tumour maintenance. Aberrant expression of the secreted signalling molecule Wnt1 generates mixed-lineage mammary tumours composed of basal and luminal tumour cell subtypes, which purportedly derive from a bipotent malignant progenitor cell residing atop a tumour cell hierarchy. Using somatic Hras mutations as clonal markers, we show that some Wnt tumours indeed conform to a hierarchical configuration, but that others unexpectedly harbour genetically distinct basal Hras mutant and luminal Hras wild-type subclones. Both subclones are required for efficient tumour propagation, which strictly depends on luminally produced Wnt1. When biclonal tumours were challenged with Wnt withdrawal to simulate targeted therapy, analysis of tumour regression and relapse revealed that basal subclones recruit heterologous Wnt-producing cells to restore tumour growth. Alternatively, in the absence of a substitute Wnt source, the original subclones often evolve to rescue Wnt pathway activation and drive relapse, either by restoring cooperation or by switching to a defector strategy. Uncovering similar modes of interclonal cooperation in human cancers may inform efforts aimed at eradicating tumour cell communities.

  18. Technical cooperation for the wider uses of Ho-166 therapeutic agents in European countries

    CERN Document Server

    Park, K B; Choi, S M; Han, K H; Hong, Y D; Park, W W; Shin, B C

    2002-01-01

    Czech has put their priority in developing the radiopharmaceuticals based on reactor produced Ho-166 and a related fabrication will be extended to other EU conturies including Germany, France, etc after a development of project. The collaboration will be based on the mutual agreement for developing the between research institutes, industries and academic institutes and further researches should be followed by the issue of developing radiopharmaceuticals using Ho-166. To strengthen the collaboration, detailed discussions for the practical collaboration have been made through the visitation to the research institution of each counter part. For implementing the collaboration between NPI and KAERI, an institutional basis technical cooperation agreement(TCA) will be concluded. Furthermore, agreement for the substantial collaboration on Ho-166 related researches will be made after the conclusion of the TCA. It will accelerate the commercialization of KAERI developed Ho-166 therapeutic agents into other European cou...

  19. Agent-Based Modeling of Mitochondria Links Sub-Cellular Dynamics to Cellular Homeostasis and Heterogeneity.

    Directory of Open Access Journals (Sweden)

    Giovanni Dalmasso

    Full Text Available Mitochondria are semi-autonomous organelles that supply energy for cellular biochemistry through oxidative phosphorylation. Within a cell, hundreds of mobile mitochondria undergo fusion and fission events to form a dynamic network. These morphological and mobility dynamics are essential for maintaining mitochondrial functional homeostasis, and alterations both impact and reflect cellular stress states. Mitochondrial homeostasis is further dependent on production (biogenesis and the removal of damaged mitochondria by selective autophagy (mitophagy. While mitochondrial function, dynamics, biogenesis and mitophagy are highly-integrated processes, it is not fully understood how systemic control in the cell is established to maintain homeostasis, or respond to bioenergetic demands. Here we used agent-based modeling (ABM to integrate molecular and imaging knowledge sets, and simulate population dynamics of mitochondria and their response to environmental energy demand. Using high-dimensional parameter searches we integrated experimentally-measured rates of mitochondrial biogenesis and mitophagy, and using sensitivity analysis we identified parameter influences on population homeostasis. By studying the dynamics of cellular subpopulations with distinct mitochondrial masses, our approach uncovered system properties of mitochondrial populations: (1 mitochondrial fusion and fission activities rapidly establish mitochondrial sub-population homeostasis, and total cellular levels of mitochondria alter fusion and fission activities and subpopulation distributions; (2 restricting the directionality of mitochondrial mobility does not alter morphology subpopulation distributions, but increases network transmission dynamics; and (3 maintaining mitochondrial mass homeostasis and responding to bioenergetic stress requires the integration of mitochondrial dynamics with the cellular bioenergetic state. Finally, (4 our model suggests sources of, and stress conditions

  20. A fault diagnosis and operation advising cooperative expert system based on multi-agent technology

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, W.; Bai, X.; Ding, J.; Fang, Z.; Li, Z. [China Electric Power Research Inst., Haidian District, Beijing (China)

    2006-07-01

    Power systems are becoming more and more complex. In addition, the amount of real-time alarm messages from the supervisory control and data acquisition, energy management systems and wide area measurement systems about switchgear and protection are also increasing to a point far beyond the operator's capacity to digest the information. Research and development of a fault diagnosis system is necessary for the timely identification of fault or malfunctioning devices and for realizing the automation functions of dynamic supervisory control system. The prevailing fault diagnosis approaches in power systems include the expert system, artificial neural network, and fault diagnosis based on optimal theory. This paper discussed the advantages and disadvantages of each of these approaches for diagnosing faults. The paper also proposed a new fault diagnosis and operational processing approach based on a cooperative expert system combined with a multi-agent architecture. For solving complex and correlative faults, the cooperative expert system can overcome the deficiency of a single expert system. It can be used not only for diagnosing complex faults in real time but also in providing timely operational advice. The proposed system has been used successfully in a district power grid in China's Shangdong province for a year. 9 refs., 4 figs.

  1. Cooperative vehicles for robust traffic congestion reduction: An analysis based on algorithmic, environmental and agent behavioral factors.

    Directory of Open Access Journals (Sweden)

    Prajakta Desai

    Full Text Available Traffic congestion continues to be a persistent problem throughout the world. As vehicle-to-vehicle communication develops, there is an opportunity of using cooperation among close proximity vehicles to tackle the congestion problem. The intuition is that if vehicles could cooperate opportunistically when they come close enough to each other, they could, in effect, spread themselves out among alternative routes so that vehicles do not all jam up on the same roads. Our previous work proposed a decentralized multiagent based vehicular congestion management algorithm entitled Congestion Avoidance and Route Allocation using Virtual Agent Negotiation (CARAVAN, wherein the vehicles acting as intelligent agents perform cooperative route allocation using inter-vehicular communication. This paper focuses on evaluating the practical applicability of this approach by testing its robustness and performance (in terms of travel time reduction, across variations in: (a environmental parameters such as road network topology and configuration; (b algorithmic parameters such as vehicle agent preferences and route cost/preference multipliers; and (c agent-related parameters such as equipped/non-equipped vehicles and compliant/non-compliant agents. Overall, the results demonstrate the adaptability and robustness of the decentralized cooperative vehicles approach to providing global travel time reduction using simple local coordination strategies.

  2. Cooperative vehicles for robust traffic congestion reduction: An analysis based on algorithmic, environmental and agent behavioral factors.

    Science.gov (United States)

    Desai, Prajakta; Loke, Seng W; Desai, Aniruddha

    2017-01-01

    Traffic congestion continues to be a persistent problem throughout the world. As vehicle-to-vehicle communication develops, there is an opportunity of using cooperation among close proximity vehicles to tackle the congestion problem. The intuition is that if vehicles could cooperate opportunistically when they come close enough to each other, they could, in effect, spread themselves out among alternative routes so that vehicles do not all jam up on the same roads. Our previous work proposed a decentralized multiagent based vehicular congestion management algorithm entitled Congestion Avoidance and Route Allocation using Virtual Agent Negotiation (CARAVAN), wherein the vehicles acting as intelligent agents perform cooperative route allocation using inter-vehicular communication. This paper focuses on evaluating the practical applicability of this approach by testing its robustness and performance (in terms of travel time reduction), across variations in: (a) environmental parameters such as road network topology and configuration; (b) algorithmic parameters such as vehicle agent preferences and route cost/preference multipliers; and (c) agent-related parameters such as equipped/non-equipped vehicles and compliant/non-compliant agents. Overall, the results demonstrate the adaptability and robustness of the decentralized cooperative vehicles approach to providing global travel time reduction using simple local coordination strategies.

  3. An adaptive approach to cooperative longitudinal platooning of heterogeneous vehicles with communication losses

    NARCIS (Netherlands)

    Abou Harfouch, Youssef; Yuan, S.; Baldi, S.; Dochain, Denis; Henrion, Didier; Peaucelle, Dimitri

    2017-01-01

    Despite the progresses in Cooperative Adaptive Cruise Control (CACC), a crucial limitation of the state-of-the-art of this control scheme is that the string stability of the platoon can be proven only when the vehicles in the platoon have identical driveline dynamics (homogeneous platoons). In

  4. 78 FR 64248 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Heterogeneous...

    Science.gov (United States)

    2013-10-28

    ... DEPARTMENT OF JUSTICE Antitrust Division Notice Pursuant to the National Cooperative Research and...; Synopsys Inc., Mountain View, CA; and Kishonti Kft (individual member), Budapest, HUNGARY, have been added... the Act. The Department of Justice published a notice in the Federal Register pursuant to Section 6(b...

  5. 78 FR 7455 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Heterogeneous...

    Science.gov (United States)

    2013-02-01

    ... DEPARTMENT OF JUSTICE Antitrust Division Notice Pursuant to the National Cooperative Research and... Tsing Hua University, Hsinchu, Taiwan, PEOPLE'S REPUBLIC OF CHINA; Ceva Inc., Mountain View, CA... the Act. The Department of Justice published a notice in the Federal Register pursuant to Section 6(b...

  6. Group Composition of Cooperative Learning: Does Heterogeneous Grouping Work in Asian Classrooms?

    Science.gov (United States)

    Thanh, Pham Thi Hong; Gillies, Robyn

    2010-01-01

    Constructing an appropriate group is important to teamwork success. Although, heterogeneous grouping is widely recommended in Western countries, this method of grouping is questioned in Asian classrooms because Asian and Western students have different cultures of learning. Unfortunately, this issue has not been addressed in any research to date.…

  7. Stationary average consensus protocol for a class of heterogeneous high-order multi-agent systems with application for aircraft

    Science.gov (United States)

    Rezaei, Mohammad Hadi; Menhaj, Mohammad Bagher

    2018-01-01

    This paper investigates the stationary average consensus problem for a class of heterogeneous-order multi-agent systems. The goal is to bring the positions of agents to the average of their initial positions while letting the other states converge to zero. To this end, three different consensus protocols are proposed. First, based on the auxiliary variables information among the agents under switching directed networks and state-feedback control, a protocol is proposed whereby all the agents achieve stationary average consensus. In the second and third protocols, by resorting to only measurements of relative positions of neighbouring agents under fixed balanced directed networks, two control frameworks are presented with two strategies based on state-feedback and output-feedback control. Finally, simulation results are given to illustrate the effectiveness of the proposed protocols.

  8. Implementing Cooperative Behavior & Control Using Open Source Technology Across Heterogeneous Vehicles

    Science.gov (United States)

    2015-03-26

    cooperative control algorithms used for multiple SUAS to perform surveillance using equal angular spacing from the ground target [16]. The algorithm...allows each SUAS in the surveillance mission to loiter around a target at an equal angular spacing from one another on the same loiter path. This...Planner has included. For instance, Mission Planner has the ability to run Python scripts. Python is a programming language like Java . With the

  9. Optimal distribution of incentives for public cooperation in heterogeneous interaction environments

    Directory of Open Access Journals (Sweden)

    Xiaojie eChen

    2014-07-01

    Full Text Available In the framework of evolutionary games with institutional reciprocity, limited incentives are at disposal for rewarding cooperators and punishing defectors. In the simplest case, it can be assumed that, depending on their strategies, all players receive equal incentives from the common pool. The question arises, however, what is the optimal distribution of institutional incentives? How should we best reward and punish individuals for cooperation to thrive? We study this problem for the public goods game on a scale-free network. We show that if the synergetic effects of group interactions are weak, the level of cooperation in the population can be maximized simply by adopting the simplest ''equal distribution'' scheme. If synergetic effects are strong, however, it is best to reward high-degree nodes more than low-degree nodes. These distribution schemes for institutional rewards are independent of payoff normalization. For institutional punishment, however, the same optimization problem is more complex, and its solution depends on whether absolute or degree-normalized payoffs are used. We find that degree-normalized payoffs require high-degree nodes be punished more lenient than low-degree nodes. Conversely, if absolute payoffs count, then high-degree nodes should be punished stronger than low-degree nodes.

  10. Cooperative learning neural network output feedback control of uncertain nonlinear multi-agent systems under directed topologies

    Science.gov (United States)

    Wang, W.; Wang, D.; Peng, Z. H.

    2017-09-01

    Without assuming that the communication topologies among the neural network (NN) weights are to be undirected and the states of each agent are measurable, the cooperative learning NN output feedback control is addressed for uncertain nonlinear multi-agent systems with identical structures in strict-feedback form. By establishing directed communication topologies among NN weights to share their learned knowledge, NNs with cooperative learning laws are employed to identify the uncertainties. By designing NN-based κ-filter observers to estimate the unmeasurable states, a new cooperative learning output feedback control scheme is proposed to guarantee that the system outputs can track nonidentical reference signals with bounded tracking errors. A simulation example is given to demonstrate the effectiveness of the theoretical results.

  11. Trends in practical applications of heterogeneous multi-agent systems : the PAAMS collection

    CERN Document Server

    Rodríguez, Juan; Mathieu, Philippe; Campbell, Andrew; Ortega, Alfonso; Adam, Emmanuel; Navarro, Elena; Ahrndt, Sebastian; Moreno, María; Julián, Vicente

    2014-01-01

    PAAMS, the International Conference on Practical Applications of Agents and Multi-Agent Systems is an evolution of the International Workshop on Practical Applications of Agents and Multi-Agent Systems. PAAMS is an international yearly tribune to present, to discuss, and to disseminate the latest developments and the most important outcomes related to real-world applications. It provides a unique opportunity to bring multi-disciplinary experts, academics and practitioners together to exchange their experience in the development of Agents and Multi-Agent Systems. This volume presents the papers that have been accepted for the 2014 special sessions: Agents Behaviours and Artificial Markets (ABAM), Agents and Mobile Devices (AM), Bio-Inspired and Multi-Agents Systems: Applications to Languages (BioMAS), Multi-Agent Systems and Ambient Intelligence (MASMAI), Self-Explaining Agents (SEA), Web Mining and Recommender systems (WebMiRes) and Intelligent Educational Systems (SSIES).

  12. Spatially correlated heterogeneous aspirations to enhance network reciprocity

    Science.gov (United States)

    Tanimoto, Jun; Nakata, Makoto; Hagishima, Aya; Ikegaya, Naoki

    2012-02-01

    Perc & Wang demonstrated that aspiring to be the fittest under conditions of pairwise strategy updating enhances network reciprocity in structured populations playing 2×2 Prisoner's Dilemma games (Z. Wang, M. Perc, Aspiring to the fittest and promoted of cooperation in the Prisoner's Dilemma game, Physical Review E 82 (2010) 021115; M. Perc, Z. Wang, Heterogeneous aspiration promotes cooperation in the Prisoner's Dilemma game, PLOS one 5 (12) (2010) e15117). Through numerical simulations, this paper shows that network reciprocity is even greater if heterogeneous aspirations are imposed. We also suggest why heterogeneous aspiration fosters network reciprocity. It distributes strategy updating speed among agents in a manner that fortifies the initially allocated cooperators' clusters against invasion. This finding prompted us to further enhance the usual heterogeneous aspiration cases for heterogeneous network topologies. We find that a negative correlation between degree and aspiration level does extend cooperation among heterogeneously structured agents.

  13. Green Cooperative Spectrum Sensing and Scheduling in Heterogeneous Cognitive Radio Networks

    KAUST Repository

    Celik, Abdulkadir

    2016-09-12

    In this paper, we consider heterogeneous cognitive radio networks (CRNs) comprising primary channels (PCs) with heterogeneous characteristics and secondary users (SUs) with various sensing and reporting qualities for different PCs. We first define the opportunity as the achievable total data rate and its cost as the energy consumption caused from sensing, reporting, and channel switching operations and formulate a joint spectrum discovery and energy efficiency objective to minimize the energy spent per unit of data rate. Then, a mixed integer nonlinear programming problem is formulated to determine: 1) the optimal subset of PCs to be scheduled for sensing; 2) the SU assignment set for each scheduled PC; and 3) sensing durations and detection thresholds of each SU on PCs it is assigned to sense. Thereafter, an equivalent convex framework is developed for specific instances of the above combinatorial problem. For comparison, optimal detection and sensing thresholds are also derived analytically under the homogeneity assumption. Based on these, a prioritized ordering heuristic is developed to order channels under the spectrum, energy, and spectrum-energy limited regimes. After that, a scheduling and assignment heuristic is proposed and is shown to perform very close to the exhaustive optimal solution. Finally, the behavior of the CRN is numerically analyzed under these regimes with respect to different numbers of SUs, PCs, and sensing qualities.

  14. Distributed coordination of heterogeneous agents using a semantic overlay network and a goal-directed graphplan planner.

    Directory of Open Access Journals (Sweden)

    António Luís Lopes

    Full Text Available In this paper, we describe a distributed coordination system that allows agents to seamlessly cooperate in problem solving by partially contributing to a problem solution and delegating the subproblems for which they do not have the required skills or knowledge to appropriate agents. The coordination mechanism relies on a dynamically built semantic overlay network that allows the agents to efficiently locate, even in very large unstructured networks, the necessary skills for a specific problem. Each agent performs partial contributions to the problem solution using a new distributed goal-directed version of the Graphplan algorithm. This new goal-directed version of the original Graphplan algorithm provides an efficient solution to the problem of "distraction", which most forward-chaining algorithms suffer from. We also discuss a set of heuristics to be used in the backward-search process of the planning algorithm in order to distribute this process amongst idle agents in an attempt to find a solution in less time. The evaluation results show that our approach is effective in building a scalable and efficient agent society capable of solving complex distributable problems.

  15. Env-glycoprotein heterogeneity as a source of apparent synergy and enhanced cooperativity in inhibition of HIV-1 infection by neutralizing antibodies and entry inhibitors

    Science.gov (United States)

    Ketas, Thomas J.; Holuigue, Sophie; Matthews, Katie; Moore, John P.

    2011-01-01

    We measured the inhibition of infectivity of HIV-1 isolates and derivative clones by combinations of neutralizing antibodies (NAbs) and other entry inhibitors in a single-cycle-replication assay. Synergy was analyzed both by the current linear and a new nonlinear method. The new method reduced spurious indications of synergy and antagonism. Synergy between NAbs was overall weaker than between other entry inhibitors, and no stronger where one ligand is known to enhance the binding of another. However, synergy was stronger for a genetically heterogeneous HIV-1 R5 isolate than for its derivative clones. Enhanced cooperativity in inhibition by combinations, compared with individual inhibitors, correlated with increased synergy at higher levels of inhibition, while being less variable. Again, cooperativity enhancement was stronger for isolates than clones. We hypothesize that genetic, post-translational or conformational heterogeneity of the Env protein and of other targets for inhibitors can yield apparent synergy and increased cooperativity between inhibitors. PMID:22018634

  16. An Immune Cooperative Particle Swarm Optimization Algorithm for Fault-Tolerant Routing Optimization in Heterogeneous Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Yifan Hu

    2012-01-01

    Full Text Available The fault-tolerant routing problem is important consideration in the design of heterogeneous wireless sensor networks (H-WSNs applications, and has recently been attracting growing research interests. In order to maintain k disjoint communication paths from source sensors to the macronodes, we present a hybrid routing scheme and model, in which multiple paths are calculated and maintained in advance, and alternate paths are created once the previous routing is broken. Then, we propose an immune cooperative particle swarm optimization algorithm (ICPSOA in the model to provide the fast routing recovery and reconstruct the network topology for path failure in H-WSNs. In the ICPSOA, mutation direction of the particle is determined by multi-swarm evolution equation, and its diversity is improved by immune mechanism, which can enhance the capacity of global search and improve the converging rate of the algorithm. Then we validate this theoretical model with simulation results. The results indicate that the ICPSOA-based fault-tolerant routing protocol outperforms several other protocols due to its capability of fast routing recovery mechanism, reliable communications, and prolonging the lifetime of WSNs.

  17. Stability Analysis of Cohesion Properties of Cooperative Agents with Limited Sensor Capability

    National Research Council Canada - National Science Library

    Liu, Yanfei

    2003-01-01

    .... Multiple robots can be designed to coordinate to accomplish certain tasks. Their cooperative behaviors resemble, to a certain extent, those of bacteria, bees and birds that work together for food in the biological world...

  18. A validated agent-based model to study the spatial and temporal heterogeneities of malaria incidence in the rainforest environment.

    Science.gov (United States)

    Pizzitutti, Francesco; Pan, William; Barbieri, Alisson; Miranda, J Jaime; Feingold, Beth; Guedes, Gilvan R; Alarcon-Valenzuela, Javiera; Mena, Carlos F

    2015-12-22

    The Amazon environment has been exposed in the last decades to radical changes that have been accompanied by a remarkable rise of both Plasmodium falciparum and Plasmodium vivax malaria. The malaria transmission process is highly influenced by factors such as spatial and temporal heterogeneities of the environment and individual-based characteristics of mosquitoes and humans populations. All these determinant factors can be simulated effectively trough agent-based models. This paper presents a validated agent-based model of local-scale malaria transmission. The model reproduces the environment of a typical riverine village in the northern Peruvian Amazon, where the malaria transmission is highly seasonal and apparently associated with flooding of large areas caused by the neighbouring river. Agents representing humans, mosquitoes and the two species of Plasmodium (P. falciparum and P. vivax) are simulated in a spatially explicit representation of the environment around the village. The model environment includes: climate, people houses positions and elevation. A representation of changes in the mosquito breeding areas extension caused by the river flooding is also included in the simulation environment. A calibration process was carried out to reproduce the variations of the malaria monthly incidence over a period of 3 years. The calibrated model is also able to reproduce the spatial heterogeneities of local scale malaria transmission. A "what if" eradication strategy scenario is proposed: if the mosquito breeding sites are eliminated through mosquito larva habitat management in a buffer area extended at least 200 m around the village, the malaria transmission is eradicated from the village. The use of agent-based models can reproduce effectively the spatiotemporal variations of the malaria transmission in a low endemicity environment dominated by river floodings like in the Amazon.

  19. Synergistic rate boosting of collagen fibrillogenesis in heterogeneous mixtures of crowding agents.

    Science.gov (United States)

    Dewavrin, Jean-Yves; Abdurrahiem, Muhammed; Blocki, Anna; Musib, Mrinal; Piazza, Francesco; Raghunath, Michael

    2015-03-26

    The competition for access to space that arises between macromolecules is the basis of the macromolecular crowding phenomenon, known to modulate biochemical reactions in subtle ways. Crowding is a highly conserved physiological condition in and around cells in metazoans, and originates from a mixture of heterogeneous biomolecules. Here, using collagen fibrillogenesis as an experimental test platform and ideas from the theory of nonideal solutions, we show that an entropy-based synergy is created by a mixture of two different populations of artificial crowders, providing small crowders with extra volume occupancy when in the vicinity of bigger crowders. We present the physiological mechanism by which synergistic effects maximize volume exclusion with the minimum amount of heterogeneous crowders, demonstrating how the evolutionarily optimized crowded conditions found in vivo can be reproduced effectively in vitro.

  20. Models for cooperative games with fuzzy relations among the agents fuzzy communication, proximity relation and fuzzy permission

    CERN Document Server

    Jiménez-Losada, Andrés

    2017-01-01

    This book offers a comprehensive introduction to cooperative game theory and a practice-oriented reference guide to new models and tools for studying bilateral fuzzy relations among several agents or players. It introduces the reader to several fuzzy models, each of which is first analyzed in the context of classical games (crisp games) and subsequently in the context of fuzzy games. Special emphasis is given to the value of Shapley, which is presented for the first time in the context of fuzzy games. Students and researchers will find here a self-contained reference guide to cooperative fuzzy games, characterized by a wealth of examples, descriptions of a wide range of possible situations, step-by-step explanations of the basic mathematical concepts involved, and easy-to-follow information on axioms and properties.

  1. Leader-following exponential consensus of fractional order nonlinear multi-agents system with hybrid time-varying delay: A heterogeneous impulsive method

    Science.gov (United States)

    Wang, Fei; Yang, Yongqing

    2017-09-01

    In this paper, we study the leader-following exponential consensus of multi-agent system. Each agent in the system is described by nonlinear fractional order differential equation. Both the internal delay and coupling delay are taken into consideration. The heterogeneous impulsive control is used for ensuring the consensus of all agents. Based on Lyapunov function method and matrix analysis, some sufficient conditions for exponential consensus are obtained. Finally, some illustrative examples are given to show the effectiveness of the obtained results.

  2. The Peace Mediator effect: Heterogeneous agents can foster consensus in continuous opinion models

    Science.gov (United States)

    Vilone, Daniele; Carletti, Timoteo; Bagnoli, Franco; Guazzini, Andrea

    2016-11-01

    Statistical mechanics has proven to be able to capture the fundamental rules underlying phenomena of social aggregation and opinion dynamics, well studied in disciplines like sociology and psychology. This approach is based on the underlying paradigm that the interesting dynamics of multi-agent systems emerge from the correct definition of few parameters governing the evolution of each individual. In this context, we propose a particular model of opinion dynamics based on the psychological construct named ;cognitive dissonance;. Our system is made of interacting individuals, the agents, each bearing only two dynamical variables (respectively ;opinion; and ;affinity;) self-consistently adjusted during time evolution. We also define two special classes of interacting entities, both acting for a peace mediation process but via different course of action: ;diplomats; and ;auctoritates;. The behavior of the system with and without peace mediators (PMs) is investigated and discussed with reference to corresponding psychological and social implications.

  3. The Impact of the Tobin Tax in a Heterogeneous Agent Model of the Foreign Exchange Market

    Czech Academy of Sciences Publication Activity Database

    Staněk, F.; Kukačka, Jiří

    2018-01-01

    Roč. 51, č. 4 (2018), s. 865-892 ISSN 0927-7099 R&D Projects: GA ČR(CZ) GBP402/12/G097 Grant - others:GA UK(CZ) 588912; GA MŠk(CZ) SVV260233 Institutional support: RVO:67985556 Keywords : Tobin tax * Foreign exchange market * Agent-based modeling * Walrasian auctioneer Subject RIV: AH - Economic s OBOR OECD: Applied Economic s, Econometrics Impact factor: 1.053, year: 2016 http://library.utia.cas.cz/separaty/2017/E/kukacka-0472380.pdf

  4. Enabling Communications in Heterogeneous Multi-Agent Systems: Electricity Markets Ontology

    Directory of Open Access Journals (Sweden)

    Gabriel SANTOS

    2016-11-01

    Full Text Available Electricity markets worldwide are complex and dynamic environments with very particular characteristics, resulting from their restructuring and evolution into regional and continental scales, along with the constant changes brought by the increasing necessity for an adequate integration of renewable energy sources. The rising complexity and unpredictability in electricity markets has increased the need for the intervenient entities in foreseeing market behaviour. Several modelling tools directed to the study of restructured wholesale electricity markets have emerged. However, they have a common limitation: the lack of interoperability between the various systems to allow the exchange of information and knowledge, to test different market models and to allow market players from different systems to interact in common market environments. This paper proposes the Electricity Markets Ontology, which integrates the essential necessary concepts related with electricity markets, while enabling an easier cooperation and adequate communication between related systems. Additionally, it can be extended and complemented according to the needs of other simulators and real systems in this area

  5. Levy-like behaviour in deterministic models of intelligent agents exploring heterogeneous environments

    International Nuclear Information System (INIS)

    Boyer, D; Miramontes, O; Larralde, H

    2009-01-01

    Many studies on animal and human movement patterns report the existence of scaling laws and power-law distributions. Whereas a number of random walk models have been proposed to explain observations, in many situations individuals actually rely on mental maps to explore strongly heterogeneous environments. In this work, we study a model of a deterministic walker, visiting sites randomly distributed on the plane and with varying weight or attractiveness. At each step, the walker minimizes a function that depends on the distance to the next unvisited target (cost) and on the weight of that target (gain). If the target weight distribution is a power law, p(k) ∼ k -β , in some range of the exponent β, the foraging medium induces movements that are similar to Levy flights and are characterized by non-trivial exponents. We explore variations of the choice rule in order to test the robustness of the model and argue that the addition of noise has a limited impact on the dynamics in strongly disordered media.

  6. Efficient heterogeneous and environmentally friendly degradation of nerve agents on a tungsten-based POM

    Energy Technology Data Exchange (ETDEWEB)

    Mizrahi, Dana M., E-mail: danami@iibr.gov.il [Department of Organic Chemistry, Israel Institute for Biological Research, P.O. Box 19, Ness Ziona 74100 (Israel); Saphier, Sigal; Columbus, Ishay [Department of Organic Chemistry, Israel Institute for Biological Research, P.O. Box 19, Ness Ziona 74100 (Israel)

    2010-07-15

    Common (chemical warfare agent) CWA decontaminants exhibit harsh and corrosive characteristics, and are harmful to the environment. In the course of our quest for active sorbents as efficient decontaminants, Keggin-type polyoxometalate (POM) (NH{sub 4}){sub 3}PW{sub 12}O{sub 40} was tested for oxidative degradation of CWAs. Although oxidation did not take place, sarin (GB) and VX were smoothly decontaminated to non-toxic products within 1 and 10 days, respectively. Degradation was carried out directly on the powder, eliminating the need for solvents. Mustard gas (HD), whose degradation is highly dependent on oxidation, was not decontaminated by this POM. Solid state MAS NMR ({sup 31}P and {sup 13}C) was utilized both for POM characterization and for decontamination studies monitoring.

  7. Efficient heterogeneous and environmentally friendly degradation of nerve agents on a tungsten-based POM

    International Nuclear Information System (INIS)

    Mizrahi, Dana M.; Saphier, Sigal; Columbus, Ishay

    2010-01-01

    Common (chemical warfare agent) CWA decontaminants exhibit harsh and corrosive characteristics, and are harmful to the environment. In the course of our quest for active sorbents as efficient decontaminants, Keggin-type polyoxometalate (POM) (NH 4 ) 3 PW 12 O 40 was tested for oxidative degradation of CWAs. Although oxidation did not take place, sarin (GB) and VX were smoothly decontaminated to non-toxic products within 1 and 10 days, respectively. Degradation was carried out directly on the powder, eliminating the need for solvents. Mustard gas (HD), whose degradation is highly dependent on oxidation, was not decontaminated by this POM. Solid state MAS NMR ( 31 P and 13 C) was utilized both for POM characterization and for decontamination studies monitoring.

  8. Costly advertising and the evolution of cooperation.

    Directory of Open Access Journals (Sweden)

    Markus Brede

    Full Text Available In this paper, I investigate the co-evolution of fast and slow strategy spread and game strategies in populations of spatially distributed agents engaged in a one off evolutionary dilemma game. Agents are characterized by a pair of traits, a game strategy (cooperate or defect and a binary 'advertising' strategy (advertise or don't advertise. Advertising, which comes at a cost [Formula: see text], allows investment into faster propagation of the agents' traits to adjacent individuals. Importantly, game strategy and advertising strategy are subject to the same evolutionary mechanism. Via analytical reasoning and numerical simulations I demonstrate that a range of advertising costs exists, such that the prevalence of cooperation is significantly enhanced through co-evolution. Linking costly replication to the success of cooperators exposes a novel co-evolutionary mechanism that might contribute towards a better understanding of the origins of cooperation-supporting heterogeneity in agent populations.

  9. Costly advertising and the evolution of cooperation.

    Science.gov (United States)

    Brede, Markus

    2013-01-01

    In this paper, I investigate the co-evolution of fast and slow strategy spread and game strategies in populations of spatially distributed agents engaged in a one off evolutionary dilemma game. Agents are characterized by a pair of traits, a game strategy (cooperate or defect) and a binary 'advertising' strategy (advertise or don't advertise). Advertising, which comes at a cost [Formula: see text], allows investment into faster propagation of the agents' traits to adjacent individuals. Importantly, game strategy and advertising strategy are subject to the same evolutionary mechanism. Via analytical reasoning and numerical simulations I demonstrate that a range of advertising costs exists, such that the prevalence of cooperation is significantly enhanced through co-evolution. Linking costly replication to the success of cooperators exposes a novel co-evolutionary mechanism that might contribute towards a better understanding of the origins of cooperation-supporting heterogeneity in agent populations.

  10. Multi-agent simulation of competitive electricity markets: Autonomous systems cooperation for European market modeling

    International Nuclear Information System (INIS)

    Santos, Gabriel; Pinto, Tiago; Morais, Hugo; Sousa, Tiago M.; Pereira, Ivo F.; Fernandes, Ricardo; Praça, Isabel; Vale, Zita

    2015-01-01

    Highlights: • Definition of an ontology allowing the communication between multi-agents systems. • Social welfare evaluation in different electricity markets. • Demonstration of the use of the proposed ontology between two multi-agents systems. • Strategic biding in electricity markets. • European electricity markets comparison. - Abstract: The electricity market restructuring, and its worldwide evolution into regional and even continental scales, along with the increasing necessity for an adequate integration of renewable energy sources, is resulting in a rising complexity in power systems operation. Several power system simulators have been developed in recent years with the purpose of helping operators, regulators, and involved players to understand and deal with this complex and constantly changing environment. The main contribution of this paper is given by the integration of several electricity market and power system models, respecting to the reality of different countries. This integration is done through the development of an upper ontology which integrates the essential concepts necessary to interpret all the available information. The continuous development of Multi-Agent System for Competitive Electricity Markets platform provides the means for the exemplification of the usefulness of this ontology. A case study using the proposed multi-agent platform is presented, considering a scenario based on real data that simulates the European Electricity Market environment, and comparing its performance using different market mechanisms. The main goal is to demonstrate the advantages that the integration of various market models and simulation platforms have for the study of the electricity markets’ evolution

  11. Distributed Scheduling to Support a Call Centre: a Co-operative Multi-Agent Approach

    NARCIS (Netherlands)

    Brazier, F.M.; Jonker, C.M.; Jungen, F.J.; Treur, J.; Nwana, H.S.

    1998-01-01

    This paper describes a multi-agent system architecture to increase the value of 24 hour a day call centre service. This system supports call centres in making appointments with clients on the basis of knowledge of employees and their schedules. Relevant activities of employees are scheduled for

  12. The technical viability of alternative blowing agents in polyisocyanurate roof insulation: A cooperative industry/government project

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.E.; Courville, G.E.; Desjarlais, A.O.; Graves, R.S.; Linkous, R.L.; McElroy, D.L.; Weaver, F.J.; Wendt, R.L.; Yarbrough, D.W.

    1993-06-01

    This report is a summary of the cooperative industry/government program to establish the viability of alternative blowing agents to chlorofluorocarbons (CFCs). The project was initiated in 1989 following two workshops that focused on needed research on thermal insulation blown with substitutes for CFC-11 and CFC-12. The project is directed by a steering committee of representatives of the sponsors and of Oak Ridge National Laboratory (ORNL). The purpose of the project is to determine if the performance of polyisocyanurate (PIR) roof insulation foam boards blown with alternate agents differs from the performance of boards blown with CFC-1. This report describes apparent thermal conductivity (k) results obtained from field and laboratory tests from 1989 to 1992 on a set of experimental PIR laminate boardstock produced to evaluate the viability of alternative hydrochlorofluorocarbons (HCFCs) as blowing agents. All boardstock was manufactured from similar formulations that were not optimized for thermal performance. Commercial broadstock made in the future may differ in performance from this set. The PIR boards were prepared with CFC-11, HCFC-123, HCFC-141b, and 50/50 and 65/35 blends of HCFC-123/HCFC-141b.

  13. Strategic orientations and cooperation of external agents in the innovation process of rural enterprises

    Directory of Open Access Journals (Sweden)

    José Francisco dos Reis Neto

    Full Text Available ABSTRACT: This article provides empirical evidence for the relationship between the market orientation, entrepreneurial orientation, and collaboration of external actors in the processes of incremental and radical innovations in rural enterprises. The research tested two sets of assumptions: first, the relation between contributions of strategic orientation and innovation processes; and second, collaborations of external stakeholders in the implementation of innovation processes. Data were collected from 208 rural enterprises and analyzed with the use of techniques of partial least squares structural equation modeling. Results showed that the market orientation contributes to the development of incremental innovation, and that the entrepreneurial orientation contributes to the implementation of the incremental and radical innovations. Specific agents (buyers, suppliers of goods and services, consultants, and others producers, collaborate positively in implementing incremental innovation; however, generic agents do not. The generic agents (universities and specialized public organizations are the ones that most intervene in radical innovations. The use of consistent theory in the areas of strategy, marketing and management in identifying that some of their causal relationships are confirmed for rural businesses unlike others, due to the structure of the market and the products produced by them.

  14. Virtual expansion of the technical vision system for smart vehicles based on multi-agent cooperation model

    Science.gov (United States)

    Krapukhina, Nina; Senchenko, Roman; Kamenov, Nikolay

    2017-12-01

    Road safety and driving in dense traffic flows poses some challenges in receiving information about surrounding moving object, some of which can be in the vehicle's blind spot. This work suggests an approach to virtual monitoring of the objects in a current road scene via a system with a multitude of cooperating smart vehicles exchanging information. It also describes the intellectual agent model, and provides methods and algorithms of identifying and evaluating various characteristics of moving objects in video flow. Authors also suggest ways for integrating the information from the technical vision system into the model with further expansion of virtual monitoring for the system's objects. Implementation of this approach can help to expand the virtual field of view for a technical vision system.

  15. The achievement of spacecraft autonomy through the thematic application of multiple cooperating intelligent agents

    Science.gov (United States)

    Rossomando, Philip J.

    1992-01-01

    A description is given of UNICORN, a prototype system developed for the purpose of investigating artificial intelligence (AI) concepts supporting spacecraft autonomy. UNICORN employs thematic reasoning, of the type first described by Rodger Schank of Northwestern University, to allow the context-sensitive control of multiple intelligent agents within a blackboard based environment. In its domain of application, UNICORN demonstrates the ability to reason teleologically with focused knowledge. Also presented are some of the lessons learned as a result of this effort. These lessons apply to any effort wherein system level autonomy is the objective.

  16. Multi-agent simulation of competitive electricity markets: Autonomous systems cooperation for European market modeling

    DEFF Research Database (Denmark)

    Santos, Gabriel; Pinto, Tiago; Morais, Hugo

    2015-01-01

    The electricity market restructuring, and its worldwide evolution into regional and even continental scales, along with the increasing necessity for an adequate integration of renewable energy sources, is resulting in a rising complexity in power systems operation. Several power system simulators...... have been developed in recent years with the purpose of helping operators, regulators, and involved players to understand and deal with this complex and constantly changing environment. The main contribution of this paper is given by the integration of several electricity market and power system models......, respecting to the reality of different countries. This integration is done through the development of an upper ontology which integrates the essential concepts necessary to interpret all the available information. The continuous development of Multi-Agent System for Competitive Electricity Markets platform...

  17. Analysis on the Load Carrying Mechanism Integrated as Heterogeneous Co-operative Manipulator in a Walking Wheelchair

    Science.gov (United States)

    Rajay Vedaraj, I. S.; Jain, Ritika; Rao, B. V. A.

    2014-07-01

    After industrial robots came into existence during 1960, the technology of robotics with the design and analysis of robots in various forms in industries as well as in domestic applications were developed. Nowadays, along with the automotive sector the robots are producing a great impact in the form of quality and production rate to register their existence reliable in various other sectors also. Robotic technology has undergone various phase translations from being tortured as humanoids to the present day manipulators. Depending upon the various forms of its existence, robot manipulators are designed as serial manipulators and parallel manipulators. Individually both types can be proved effective though both have various drawbacks in design and the kinematic analysis. The versatility of robots can be increased by making them work in an environment where the same work volume is shared by more than one manipulator. This work volume can be identified as co-operative work volume of those manipulators. Here the interference of manipulators in the work volume of other manipulators is possible and is made obstacle free. The main advantage of co-operative manipulators is that when a number of independent manipulators are put together in a cooperative work envelope the efficiency and ability to perform tasks is greatly enhanced. The main disadvantage of the co-operative manipulators lies in the complication of its design even for a simple application, in almost all fields. In this paper, a cooperative design of robot manipulators to work in co-operative work environment is done and analysed for its efficacy. In the industrial applications when robotic manipulators are put together in more numbers, the trajectory planning becomes the tough task in the work cell. Proper design can remove the design defects of the cooperative manipulators and can be utilized in a more efficient way. In the proposed research paper an analysis is made on such a type of cooperative manipulator

  18. Analysis on the Load Carrying Mechanism Integrated as Heterogeneous Co-operative Manipulator in a Walking Wheelchair

    International Nuclear Information System (INIS)

    Vedaraj, I S Rajay; Jain, Ritika; Rao, B V A

    2014-01-01

    After industrial robots came into existence during 1960, the technology of robotics with the design and analysis of robots in various forms in industries as well as in domestic applications were developed. Nowadays, along with the automotive sector the robots are producing a great impact in the form of quality and production rate to register their existence reliable in various other sectors also. Robotic technology has undergone various phase translations from being tortured as humanoids to the present day manipulators. Depending upon the various forms of its existence, robot manipulators are designed as serial manipulators and parallel manipulators. Individually both types can be proved effective though both have various drawbacks in design and the kinematic analysis. The versatility of robots can be increased by making them work in an environment where the same work volume is shared by more than one manipulator. This work volume can be identified as co-operative work volume of those manipulators. Here the interference of manipulators in the work volume of other manipulators is possible and is made obstacle free. The main advantage of co-operative manipulators is that when a number of independent manipulators are put together in a cooperative work envelope the efficiency and ability to perform tasks is greatly enhanced. The main disadvantage of the co-operative manipulators lies in the complication of its design even for a simple application, in almost all fields. In this paper, a cooperative design of robot manipulators to work in co-operative work environment is done and analysed for its efficacy. In the industrial applications when robotic manipulators are put together in more numbers, the trajectory planning becomes the tough task in the work cell. Proper design can remove the design defects of the cooperative manipulators and can be utilized in a more efficient way. In the proposed research paper an analysis is made on such a type of cooperative manipulator

  19. Distributed cooperative H∞ optimal tracking control of MIMO nonlinear multi-agent systems in strict-feedback form via adaptive dynamic programming

    Science.gov (United States)

    Luy, N. T.

    2018-04-01

    The design of distributed cooperative H∞ optimal controllers for multi-agent systems is a major challenge when the agents' models are uncertain multi-input and multi-output nonlinear systems in strict-feedback form in the presence of external disturbances. In this paper, first, the distributed cooperative H∞ optimal tracking problem is transformed into controlling the cooperative tracking error dynamics in affine form. Second, control schemes and online algorithms are proposed via adaptive dynamic programming (ADP) and the theory of zero-sum differential graphical games. The schemes use only one neural network (NN) for each agent instead of three from ADP to reduce computational complexity as well as avoid choosing initial NN weights for stabilising controllers. It is shown that despite not using knowledge of cooperative internal dynamics, the proposed algorithms not only approximate values to Nash equilibrium but also guarantee all signals, such as the NN weight approximation errors and the cooperative tracking errors in the closed-loop system, to be uniformly ultimately bounded. Finally, the effectiveness of the proposed method is shown by simulation results of an application to wheeled mobile multi-robot systems.

  20. Costly Advertising and the Evolution of Cooperation

    Science.gov (United States)

    Brede, Markus

    2013-01-01

    In this paper, I investigate the co-evolution of fast and slow strategy spread and game strategies in populations of spatially distributed agents engaged in a one off evolutionary dilemma game. Agents are characterized by a pair of traits, a game strategy (cooperate or defect) and a binary ‘advertising’ strategy (advertise or don’t advertise). Advertising, which comes at a cost , allows investment into faster propagation of the agents’ traits to adjacent individuals. Importantly, game strategy and advertising strategy are subject to the same evolutionary mechanism. Via analytical reasoning and numerical simulations I demonstrate that a range of advertising costs exists, such that the prevalence of cooperation is significantly enhanced through co-evolution. Linking costly replication to the success of cooperators exposes a novel co-evolutionary mechanism that might contribute towards a better understanding of the origins of cooperation-supporting heterogeneity in agent populations. PMID:23861752

  1. A further analysis of the role of heterogeneity in coevolutionary spatial games

    Science.gov (United States)

    Cardinot, Marcos; Griffith, Josephine; O'Riordan, Colm

    2018-03-01

    Heterogeneity has been studied as one of the most common explanations of the puzzle of cooperation in social dilemmas. A large number of papers have been published discussing the effects of increasing heterogeneity in structured populations of agents, where it has been established that heterogeneity may favour cooperative behaviour if it supports agents to locally coordinate their strategies. In this paper, assuming an existing model of a heterogeneous weighted network, we aim to further this analysis by exploring the relationship (if any) between heterogeneity and cooperation. We adopt a weighted network which is fully populated by agents playing both the Prisoner's Dilemma or the Optional Prisoner's Dilemma games with coevolutionary rules, i.e., not only the strategies but also the link weights evolve over time. Surprisingly, results show that the heterogeneity of link weights (states) on their own does not always promote cooperation; rather cooperation is actually favoured by the increase in the number of overlapping states and not by the heterogeneity itself. We believe that these results can guide further research towards a more accurate analysis of the role of heterogeneity in social dilemmas.

  2. Developing a Distributed Consensus-Based Cooperative Adaptive Cruise Control System for Heterogeneous Vehicles with Predecessor Following Topology

    Directory of Open Access Journals (Sweden)

    Ziran Wang

    2017-01-01

    Full Text Available Connected and automated vehicle (CAV has become an increasingly popular topic recently. As an application, Cooperative Adaptive Cruise Control (CACC systems are of high interest, allowing CAVs to communicate with each other and coordinating their maneuvers to form platoons, where one vehicle follows another with a constant velocity and/or time headway. In this study, we propose a novel CACC system, where distributed consensus algorithm and protocol are designed for platoon formation, merging maneuvers, and splitting maneuvers. Predecessor following information flow topology is adopted for the system, where each vehicle only communicates with its following vehicle to reach consensus of the whole platoon, making the vehicle-to-vehicle (V2V communication fast and accurate. Moreover, different from most studies assuming the type and dynamics of all the vehicles in a platoon to be homogenous, we take into account the length, location of GPS antenna on vehicle, and braking performance of different vehicles. A simulation study has been conducted under scenarios including normal platoon formation, platoon restoration from disturbances, and merging and splitting maneuvers. We have also carried out a sensitivity analysis on the distributed consensus algorithm, investigating the effect of the damping gain on convergence rate, driving comfort, and driving safety of the system.

  3. Cooperative Dynamics in Lattice-Embedded Scale-Free Networks

    International Nuclear Information System (INIS)

    Shang Lihui; Zhang Mingji; Yang Yanqing

    2009-01-01

    We investigate cooperative behaviors of lattice-embedded scale-free networking agents in the prisoner's dilemma game model by employing two initial strategy distribution mechanisms, which are specific distribution to the most connected sites (hubs) and random distribution. Our study indicates that the game dynamics crucially depends on the underlying spatial network structure with different strategy distribution mechanism. The cooperators' specific distribution contributes to an enhanced level of cooperation in the system compared with random one, and cooperation is robust to cooperators' specific distribution but fragile to defectors' specific distribution. Especially, unlike the specific case, increasing heterogeneity of network does not always favor the emergence of cooperation under random mechanism. Furthermore, we study the geographical effects and find that the graphically constrained network structure tends to improve the evolution of cooperation in random case and in specific one for a large temptation to defect.

  4. A detailed heterogeneous agent model for a single asset financial market with trading via an order book.

    Directory of Open Access Journals (Sweden)

    Roberto Mota Navarro

    Full Text Available We present an agent based model of a single asset financial market that is capable of replicating most of the non-trivial statistical properties observed in real financial markets, generically referred to as stylized facts. In our model agents employ strategies inspired on those used in real markets, and a realistic trade mechanism based on a double auction order book. We study the role of the distinct types of trader on the return statistics: specifically, correlation properties (or lack thereof, volatility clustering, heavy tails, and the degree to which the distribution can be described by a log-normal. Further, by introducing the practice of "profit taking", our model is also capable of replicating the stylized fact related to an asymmetry in the distribution of losses and gains.

  5. A detailed heterogeneous agent model for a single asset financial market with trading via an order book.

    Science.gov (United States)

    Mota Navarro, Roberto; Larralde, Hernán

    2017-01-01

    We present an agent based model of a single asset financial market that is capable of replicating most of the non-trivial statistical properties observed in real financial markets, generically referred to as stylized facts. In our model agents employ strategies inspired on those used in real markets, and a realistic trade mechanism based on a double auction order book. We study the role of the distinct types of trader on the return statistics: specifically, correlation properties (or lack thereof), volatility clustering, heavy tails, and the degree to which the distribution can be described by a log-normal. Further, by introducing the practice of "profit taking", our model is also capable of replicating the stylized fact related to an asymmetry in the distribution of losses and gains.

  6. Teamwork in Multi-Agent Systems A Formal Approach

    CERN Document Server

    Dunin-Keplicz, Barbara Maria

    2010-01-01

    What makes teamwork tick?. Cooperation matters, in daily life and in complex applications. After all, many tasks need more than a single agent to be effectively performed. Therefore, teamwork rules!. Teams are social groups of agents dedicated to the fulfilment of particular persistent tasks. In modern multiagent environments, heterogeneous teams often consist of autonomous software agents, various types of robots and human beings. Teamwork in Multi-agent Systems: A Formal Approach explains teamwork rules in terms of agents' attitudes and their complex interplay. It provides the first comprehe

  7. Distributed-observer-based cooperative control for synchronization of linear discrete-time multi-agent systems.

    Science.gov (United States)

    Liang, Hongjing; Zhang, Huaguang; Wang, Zhanshan

    2015-11-01

    This paper considers output synchronization of discrete-time multi-agent systems with directed communication topologies. The directed communication graph contains a spanning tree and the exosystem as its root. Distributed observer-based consensus protocols are proposed, based on the relative outputs of neighboring agents. A multi-step algorithm is presented to construct the observer-based protocols. In light of the discrete-time algebraic Riccati equation and internal model principle, synchronization problem is completed. At last, numerical simulation is provided to verify the effectiveness of the theoretical results. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  8. Unified Generic Geometric-Decompositions for Consensus or Flocking Systems of Cooperative Agents and Fast Recalculations of Decomposed Subsystems Under Topology-Adjustments.

    Science.gov (United States)

    Li, Wei

    2016-06-01

    This paper considers a unified geometric projection approach for: 1) decomposing a general system of cooperative agents coupled via Laplacian matrices or stochastic matrices and 2) deriving a centroid-subsystem and many shape-subsystems, where each shape-subsystem has the distinct properties (e.g., preservation of formation and stability of the original system, sufficiently simple structures and explicit formation evolution of agents, and decoupling from the centroid-subsystem) which will facilitate subsequent analyses. Particularly, this paper provides an additional merit of the approach: considering adjustments of coupling topologies of agents which frequently occur in system design (e.g., to add or remove an edge, to move an edge to a new place, and to change the weight of an edge), the corresponding new shape-subsystems can be derived by a few simple computations merely from the old shape-subsystems and without referring to the original system, which will provide further convenience for analysis and flexibility of choice. Finally, such fast recalculations of new subsystems under topology adjustments are provided with examples.

  9. Interacting agents in finance

    NARCIS (Netherlands)

    Hommes, C.; Durlauf, S.N.; Blume, L.E.

    2008-01-01

    Interacting agents in finance represent a behavioural, agent-based approach in which financial markets are viewed as complex adaptive systems consisting of many boundedly rational agents interacting through simple heterogeneous investment strategies, constantly adapting their behaviour in response

  10. Cooperative Trust Games

    Science.gov (United States)

    2013-01-01

    the more widely recognized competitive (non-cooperative) game theory. Cooperative game theory focuses on what groups of self-interested agents can...provides immediate justification for using non-cooperative game theory as the basis for modeling the purely competitive agents. 2.4. Superadditive...the competitive and altruistic contributions of the subset team. Definition: Given a payoff function ( ) in a subset team game , the total marginal

  11. Fundamental properties of cooperative contagion processes

    Science.gov (United States)

    Chen, Li; Ghanbarnejad, Fakhteh; Brockmann, Dirk

    2017-10-01

    We investigate the effects of cooperativity between contagion processes that spread and persist in a host population. We propose and analyze a dynamical model in which individuals that are affected by one transmissible agent A exhibit a higher than baseline propensity of being affected by a second agent B and vice versa. The model is a natural extension of the traditional susceptible-infected-susceptible model used for modeling single contagion processes. We show that cooperativity changes the dynamics of the system considerably when cooperativity is strong. The system exhibits discontinuous phase transitions not observed in single agent contagion, multi-stability, a separation of the traditional epidemic threshold into different thresholds for inception and extinction as well as hysteresis. These properties are robust and are corroborated by stochastic simulations on lattices and generic network topologies. Finally, we investigate wave propagation and transients in a spatially extended version of the model and show that especially for intermediate values of baseline reproduction ratios the system is characterized by various types of wave-front speeds. The system can exhibit spatially heterogeneous stationary states for some parameters and negative front speeds (receding wave fronts). The two agent model can be employed as a starting point for more complex contagion processes, involving several interacting agents, a model framework particularly suitable for modeling the spread and dynamics of microbiological ecosystems in host populations.

  12. Fundamental properties of cooperative contagion processes

    International Nuclear Information System (INIS)

    Chen, Li; Ghanbarnejad, Fakhteh; Brockmann, Dirk

    2017-01-01

    We investigate the effects of cooperativity between contagion processes that spread and persist in a host population. We propose and analyze a dynamical model in which individuals that are affected by one transmissible agent A exhibit a higher than baseline propensity of being affected by a second agent B and vice versa. The model is a natural extension of the traditional susceptible-infected-susceptible model used for modeling single contagion processes. We show that cooperativity changes the dynamics of the system considerably when cooperativity is strong. The system exhibits discontinuous phase transitions not observed in single agent contagion, multi-stability, a separation of the traditional epidemic threshold into different thresholds for inception and extinction as well as hysteresis. These properties are robust and are corroborated by stochastic simulations on lattices and generic network topologies. Finally, we investigate wave propagation and transients in a spatially extended version of the model and show that especially for intermediate values of baseline reproduction ratios the system is characterized by various types of wave-front speeds. The system can exhibit spatially heterogeneous stationary states for some parameters and negative front speeds (receding wave fronts). The two agent model can be employed as a starting point for more complex contagion processes, involving several interacting agents, a model framework particularly suitable for modeling the spread and dynamics of microbiological ecosystems in host populations. (paper)

  13. Index-Based Insurance Contracts to FOSTER Cooperation Between Agents Exposed to Uncorrelated Drought and Flooding Risks

    Science.gov (United States)

    Denaro, S.; Giuliani, M.; Castelletti, A.; Characklis, G. W.

    2017-12-01

    Worldwide, conflict over shared water resources is exacerbated by population growth, economic development and climate change. In multi-purpose water systems, stakeholders can face higher financial risks as a consequence of increased hydrological uncertainty and recurrent extreme events. In this context, a financial hedging tool able to bundle together the uncorrelated risks faced by different stakeholders may be an efficient solution to both foster cooperation and manage the financial losses associated with extreme events. In this work we explore the potential of risk diversification strategies involving index-based insurance joint contract solutions, to manage financial risk in a multi-purpose water system prone to both drought and flood risk. Risk diversification can allow for reduced insurance premiums in situations in which the bundled risks are entirely, or mostly, uncorrelated. Jointly covering flood and drought related risks from competing users in the same geographic area represents a novel application. The approach is demonstrated using a case study on Lake Maggiore, a regulated lake whose management is highly controversial due to numerous and competing human activities. In particular we focus on the ongoing conflict among the lakeshore population, affected by flood risk, and the downstream farmers' districts, facing drought related losses. Results are promising and indicate that bundling uncorrelated risks from competing users is beneficial to both promoting insurance premium affordability and facilitating collaboration schemes at the catchment scale.

  14. Investigating the heterogeneity of alkylating agents' efficacy and toxicity between sexes: A systematic review and meta-analysis of randomized trials comparing cyclophosphamide and ifosfamide (MAIAGE study).

    Science.gov (United States)

    Fresneau, Brice; Hackshaw, A; Hawkins, D S; Paulussen, M; Anderson, J R; Judson, I; Litière, S; Dirksen, U; Lewis, I; van den Berg, H; Gaspar, N; Gelderblom, H; Whelan, J; Boddy, A V; Wheatley, K; Pignon, J P; De Vathaire, F; Le Deley, M C; Le Teuff, G

    2017-08-01

    A marginal interaction between sex and the type of alkylating agent was observed for event-free survival in the Euro-EWING99-R1 randomized controlled trial (RCT) comparing cyclophosphamide and ifosfamide in Ewing sarcoma. To further evaluate this interaction, we performed an individual patient data meta-analysis of RCTs assessing cyclophosphamide versus ifosfamide in any type of cancer. A literature search produced two more eligible RCTs (EICESS92 and IRS-IV). The endpoints were progression-free survival (PFS, main endpoint) and overall survival (OS). The hazard ratios (HRs) of the treatment-by-sex interaction and their 95% confidence interval (95% CI) were assessed using stratified multivariable Cox models. Heterogeneity of the interaction across age categories and trials was explored. We also assessed this interaction for severe acute toxicity using logistic models. The meta-analysis comprised 1,528 pediatric and young adult sarcoma patients from three RCTs: Euro-EWING99-R1 (n = 856), EICESS92 (n = 155), and IRS-IV (n = 517). There were 224 PFS events in Euro-EWING99-R1 and 200 in the validation set (EICESS92 + IRS-IV), and 171 and 154 deaths in each dataset, respectively. The estimated treatment-by-sex interaction for PFS in Euro-EWING99-R1 (HR = 1.73, 95% CI = 1.00-3.00) was not replicated in the validation set (HR = 0.97, 95% CI = 0.55-1.72), without heterogeneity across trials (P = 0.62). In the pooled analysis, the treatment-by-sex interaction was not significant (HR = 1.31, 95% CI = 0.89-1.95, P = 0.17), without heterogeneity across age categories (P = 0.88) and trials (P = 0.36). Similar results were observed for OS. No significant treatment-by-sex interaction was observed for leucopenia/neutropenia (P = 0.45), infection (P = 0.64), or renal toxicity (P = 0.20). Our meta-analysis did not confirm the hypothesis of a treatment-by-sex interaction on efficacy or toxicity outcomes. © 2017 Wiley Periodicals, Inc.

  15. Heterogeneous Agents in Financial Markets

    NARCIS (Netherlands)

    Zwinkels, R.C.J.

    2009-01-01

    In the previous decades, evidence against the efficient market hypothesis has been mounting. As a result, the behavioral finance literature has emerged, which embeds psychological influences in financial economics. The current thesis fits within the behavioral finance literature, and is focused on

  16. Evolutionary games played by multi-agent system with different memory capacity

    Science.gov (United States)

    Zhang, Jianlei; Zhang, Chunyan

    2015-06-01

    The evolution of cooperation is still an enigma. Resolution of cooperative dilemma is a hot topic as a perplexing interdisciplinary project, and has captured wide attention of researchers from many disciplines as a multidisciplinary field. Our main concern is the design of a networked evolutionary game model in which players show difference in memory capability. The idea of different memory capacities has its origin on the pervasive individual heterogeneity of real agents in nature. It is concluded that this proposed multiple memory capacity stimulates cooperation in lattice-structured populations. The networking effect is also investigated via a scale free network which is associated with the heterogeneous populations structure. Interestingly, results suggest that the effectiveness of a heterogeneous network at fostering cooperation is reduced in the presence of individual memory here. A thorough inquiry in the coevolutionary dynamics of individual memory and spatial structure in evolutionary games is planned for the immediate future.

  17. Evaluation of accessory cell heterogeneity. I. Differential accessory cell requirement for T helper cell activation and for T-B cooperation.

    Science.gov (United States)

    Ramila, G; Studer, S; Kennedy, M; Sklenar, I; Erb, P

    1985-01-01

    Several Ia+ tumor cell lines and peritoneal exudate macrophages were tested as accessory cells (AC) for the activation of antigen-specific T cells and for T-B cooperation. The macrophages and all the Ia+ tumor lines tested induced the release of lymphokines from T cells in a major histocompatibility complex (MHC)-restricted fashion and reconstituted the antibody responses of AC-depleted spleen cells or of purified T and B cells. However, only the normal macrophages but none of the tumor lines induced carrier-specific T helper (Th) cells which help B cells for specific antihapten antibody responses by linked recognition. For T-B cooperation accessory cells were also required, but in contrast to Th cell activation any type of Ia+ AC (e.g. macrophage or tumor line) was effective. Strong MHC-restriction between the lymphocytes and the AC was seen if antigen-pulsed AC were added into the AC-depleted T-B cooperation cultures. If the AC and antigen were concomitantly added to the AC-depleted T-B cultures, MHC-restriction was less obvious. Concanavalin A supernatant reconstituted the response of AC-depleted T-B cultures provided antigen-specific Th cells and the hapten-carrier conjugate were present. If, however, tumor line-activated T cells were added instead of macrophage-induced Th cells, no cooperation with B cells took place even in the presence of Con A supernatant. The results obtained demonstrate a differential AC requirement for the induction of Th cells depending on the differentiation stage of the Th cells.

  18. Understanding the nature of cooperation variability

    DEFF Research Database (Denmark)

    Fosgaard, Toke Reinholt; Hansen, Lars Gårn; Wengström, Erik Roland

    2014-01-01

    effects and the heterogeneity of cooperation behavior. We find that framing only has a small effect on the average level of cooperation but a substantial effect on behavioral heterogeneity explained almost exclusively by a corresponding change in the heterogeneity of beliefs about other subjects' behavior...

  19. Study of a Dynamic Cooperative Trading Queue Routing Control Scheme for Freeways and Facilities with Parallel Queues

    OpenAIRE

    Lloret-Batlle, Roger; Jayakrishnan, R.

    2018-01-01

    This article explores the coalitional stability of a new cooperative control policy for freeways and parallel queuing facilities with multiple servers. Based on predicted future delays per queue or lane, a VOT-heterogeneous population of agents can agree to switch lanes or queues and transfer payments to each other in order to minimize the total cost of the incoming platoon. The strategic interaction is captured by an n-level Stackelberg model with coalitions, while the cooperative structure ...

  20. Heterogeneity and option pricing

    NARCIS (Netherlands)

    Benninga, Simon; Mayshar, Joram

    2000-01-01

    An economy with agents having constant yet heterogeneous degrees of relative risk aversion prices assets as though there were a single decreasing relative risk aversion pricing representative agent. The pricing kernel has fat tails and option prices do not conform to the Black-Scholes formula.

  1. Cooperative information agents and communication

    NARCIS (Netherlands)

    Verharen, E.; Dignum, F.P.M.

    1997-01-01

    Research in Information Systems has switched its focus from data to communication. The communication between different autonomous Information Systems requires a certain amount of intelligence of each system. The system should be able to know which queries it can/may handle and also be able to

  2. Cooperation, compensation and transition

    NARCIS (Netherlands)

    Ju, Y.

    2004-01-01

    Cooperation and compensation are two important and well-linked issues in economics. The central question in cooperation is how to share the joint gains among participating players. Compensation is a specific aspect of surplus sharing problems providing incentives for agents to sacrifice their own

  3. Cooperative Bacterial Foraging Optimization

    Directory of Open Access Journals (Sweden)

    Hanning Chen

    2009-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a novel optimization algorithm based on the social foraging behavior of E. coli bacteria. This paper presents a variation on the original BFO algorithm, namely, the Cooperative Bacterial Foraging Optimization (CBFO, which significantly improve the original BFO in solving complex optimization problems. This significant improvement is achieved by applying two cooperative approaches to the original BFO, namely, the serial heterogeneous cooperation on the implicit space decomposition level and the serial heterogeneous cooperation on the hybrid space decomposition level. The experiments compare the performance of two CBFO variants with the original BFO, the standard PSO and a real-coded GA on four widely used benchmark functions. The new method shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  4. Soft cooperation systems and games

    Science.gov (United States)

    Fernández, J. R.; Gallego, I.; Jiménez-Losada, A.; Ordóñez, M.

    2018-04-01

    A cooperative game for a set of agents establishes a fair allocation of the profit obtained for their cooperation. In order to obtain this allocation, a characteristic function is known. It establishes the profit of each coalition of agents if this coalition decides to act alone. Originally players are considered symmetric and then the allocation only depends on the characteristic function; this paper is about cooperative games with an asymmetric set of agents. We introduced cooperative games with a soft set of agents which explains those parameters determining the asymmetry among them in the cooperation. Now the characteristic function is defined not over the coalitions but over the soft coalitions, namely the profit depends not only on the formed coalition but also on the attributes considered for the players in the coalition. The best known of the allocation rules for cooperative games is the Shapley value. We propose a Shapley kind solution for soft games.

  5. Network Management using Multi-Agents System

    Directory of Open Access Journals (Sweden)

    Nestor DUQUE

    2013-07-01

    Full Text Available This paper aims to present a multiagent system for network management. The models developed for the proposed system defines certain intelligent agents interact to achieve the objectives and requirements of the multiagent organization.These agents have the property of being adaptive, acquire knowledge and skills to make decisions according to the actual state of the network that is represented in the information base, MIB, SNMP devices. The ideal state of the network policy is defined by the end user entered, which contain the value that should have performance variables and other parameters such as the frequency with which these variables should be monitored.. An agent based architecture increase the integration, adaptability, cooperation, autonomy and the efficient operation in heterogeneous environment in the network supervision. 

  6. Network Management using Multi-Agents System

    Directory of Open Access Journals (Sweden)

    Gustavo ISAZA

    2012-12-01

    Full Text Available This paper aims to present a multiagent system for network management. The models developed for the proposed system defines certain intelligent agents interact to achieve the objectives and requirements of the multiagent organization.These agents have the property of being adaptive, acquire knowledge and skills to make decisions according to the actual state of the network that is represented in the information base, MIB, SNMP devices. The ideal state of the network policy is defined by the end user entered, which contain the value that should have performance variables and other parameters such as the frequency with which these variables should be monitored.. An agent based architecture increase the integration, adaptability, cooperation, autonomy and the efficient operation in heterogeneous environment in the network supervision. 

  7. Interest rate rules with heterogeneous expectations

    NARCIS (Netherlands)

    Anufriev, M.; Assenza, T.; Hommes, C.; Massaro, D.

    2011-01-01

    The recent macroeconomic literature stresses the importance of managing heterogeneous expectations in the formulation of monetary policy. We use a simple frictionless DSGE model to investigate inflation dynamics under alternative interest rate rules when agents have heterogeneous expectations and

  8. Investigating the heterogeneity of alkylating agents' efficacy and toxicity between sexes: A systematic review and meta-analysis of randomized trials comparing cyclophosphamide and ifosfamide (MAIAGE study)

    NARCIS (Netherlands)

    Fresneau, Brice; Hackshaw, A.; Hawkins, D. S.; Paulussen, M.; Anderson, J. R.; Judson, I.; Litière, S.; Dirksen, U.; Lewis, I.; van den Berg, H.; Gaspar, N.; Gelderblom, H.; Whelan, J.; Boddy, A. V.; Wheatley, K.; Pignon, J. P.; de Vathaire, F.; Le Deley, M. C.; Le Teuff, G.

    2017-01-01

    A marginal interaction between sex and the type of alkylating agent was observed for event-free survival in the Euro-EWING99-R1 randomized controlled trial (RCT) comparing cyclophosphamide and ifosfamide in Ewing sarcoma. To further evaluate this interaction, we performed an individual patient data

  9. 基于多智能体协同的角色互换策略的研究应用%Research Application Based on Strategy of Multi-Agent Cooperative Role Exchange

    Institute of Scientific and Technical Information of China (English)

    章成飞; 程泽凯; 秦锋

    2013-01-01

    Multi-Agent cooperative technology is an important branch in the field of Artificial Intelligence ( AI) . Robot football race pro-vides a test platform for the study of Multi-Agent cooperative technology. The football player named Agent in the robot simulation foot-ball race has both number attribute and role attribute. It makes Agent in the robot simulation football race as the research subject. Model for Agent with online coach mechanism and put forward the tactics to identify the counterparts as well as the strategy of football players'dynamic role exchange. In the underlying 2D of Agent,programming comes into effect. When one robot simulation football team tests with the other one,the winning probability is going to be raised by a big margin,which demonstrates the efficiency of this algorithm. And the algorithm can also improve attack ability of the football team.%多智能体协同技术是人工智能领域的一个重要分支。机器人足球比赛为多智能体协同技术的研究提供了一个测试平台,仿真机器人足球比赛球员Agent具有号码属性与角色属性。文中以仿真机器人足球比赛中的球员Agent为研究对象,利用在线教练机制对球员Agent进行建模,提出了对手角色识别策略以及基于多智能体协同的球员Agent动态角色互换策略。在Agent2D底层中编程实现,与某球队进行测试,胜率大大增加,结果表明了该算法的有效性,该算法可提高球队的进攻能力。

  10. International cooperation

    International Nuclear Information System (INIS)

    2008-01-01

    In this chapter international cooperation of the Division for Radiation Safety, NPP Decommissioning and Radwaste Management of the VUJE, a. s. is presented. Very important is cooperation with the International Atomic Energy Agency. This cooperation has various forms - national and regional projects of technical cooperation, coordinated research activities, participation of our experts in preparation of the IAEA documentation etc.

  11. How feeling betrayed affects cooperation.

    Science.gov (United States)

    Ramazi, Pouria; Hessel, Jop; Cao, Ming

    2015-01-01

    For a population of interacting self-interested agents, we study how the average cooperation level is affected by some individuals' feelings of being betrayed and guilt. We quantify these feelings as adjusted payoffs in asymmetric games, where for different emotions, the payoff matrix takes the structure of that of either a prisoner's dilemma or a snowdrift game. Then we analyze the evolution of cooperation in a well-mixed population of agents, each of whom is associated with such a payoff matrix. At each time-step, an agent is randomly chosen from the population to update her strategy based on the myopic best-response update rule. According to the simulations, decreasing the feeling of being betrayed in a portion of agents does not necessarily increase the level of cooperation in the population. However, this resistance of the population against low-betrayal-level agents is effective only up to some extend that is explicitly determined by the payoff matrices and the number of agents associated with these matrices. Two other models are also considered where the betrayal factor of an agent fluctuates as a function of the number of cooperators and defectors that she encounters. Unstable behaviors are observed for the level of cooperation in these cases; however, we show that one can tune the parameters in the function to make the whole population become cooperative or defective.

  12. How feeling betrayed affects cooperation.

    Directory of Open Access Journals (Sweden)

    Pouria Ramazi

    Full Text Available For a population of interacting self-interested agents, we study how the average cooperation level is affected by some individuals' feelings of being betrayed and guilt. We quantify these feelings as adjusted payoffs in asymmetric games, where for different emotions, the payoff matrix takes the structure of that of either a prisoner's dilemma or a snowdrift game. Then we analyze the evolution of cooperation in a well-mixed population of agents, each of whom is associated with such a payoff matrix. At each time-step, an agent is randomly chosen from the population to update her strategy based on the myopic best-response update rule. According to the simulations, decreasing the feeling of being betrayed in a portion of agents does not necessarily increase the level of cooperation in the population. However, this resistance of the population against low-betrayal-level agents is effective only up to some extend that is explicitly determined by the payoff matrices and the number of agents associated with these matrices. Two other models are also considered where the betrayal factor of an agent fluctuates as a function of the number of cooperators and defectors that she encounters. Unstable behaviors are observed for the level of cooperation in these cases; however, we show that one can tune the parameters in the function to make the whole population become cooperative or defective.

  13. Models in cooperative game theory

    CERN Document Server

    Branzei, Rodica; Tijs, Stef

    2008-01-01

    This book investigates models in cooperative game theory in which the players have the possibility to cooperate partially. In a crisp game the agents are either fully involved or not involved at all in cooperation with some other agents, while in a fuzzy game players are allowed to cooperate with infinite many different participation levels, varying from non-cooperation to full cooperation. A multi-choice game describes the intermediate case in which each player may have a fixed number of activity levels. Different set and one-point solution concepts for these games are presented. The properties of these solution concepts and their interrelations on several classes of crisp, fuzzy, and multi-choice games are studied. Applications of the investigated models to many economic situations are indicated as well. The second edition is highly enlarged and contains new results and additional sections in the different chapters as well as one new chapter.

  14. Behavioral heterogeneity in stock prices

    NARCIS (Netherlands)

    Boswijk, H.P.; Hommes, C.H.; Manzan, S.

    2007-01-01

    We estimate a dynamic asset pricing model characterized by heterogeneous boundedly rational agents. The fundamental value of the risky asset is publicly available to all agents, but they have different beliefs about the persistence of deviations of stock prices from the fundamental benchmark. An

  15. Promotion of cooperation in the form C0C1D classified by 'degree grads' in a scale-free network

    International Nuclear Information System (INIS)

    Zhao, Li; Ye, Xiang-Jun; Huang, Zi-Gang; Sun, Jin-Tu; Yang, Lei; Wang, Ying-Hai; Do, Younghae

    2010-01-01

    In this paper, we revisit the issue of the public goods game (PGG) on a heterogeneous graph. By introducing a new effective topology parameter, 'degree grads' ψ, we clearly classify the agents into three kinds, namely, C 0 , C 1 , and D. The mechanism for the heterogeneous topology promoting cooperation is discussed in detail from the perspective of C 0 C 1 D, which reflects the fact that the unreasoning imitation behaviour of C 1 agents, who are 'cheated' by the well-paid C 0 agents inhabiting special positions, stabilizes the formation of the cooperation community. The analytical and simulation results for certain parameters are found to coincide well with each other. The C 0 C 1 D case provides a picture of the actual behaviours in real society and thus is potentially of interest

  16. Conflictual cooperation

    DEFF Research Database (Denmark)

    Axel, Erik

    2011-01-01

    , cooperation appeared as the continuous reworking of contradictions in the local arrangement of societal con- ditions. Subjects were distributed and distributed themselves according to social privileges, resources, and dilemmas in cooperation. Here, the subjects’ activities and understandings took form from...

  17. Cooperative tumour cell membrane targeted phototherapy

    Science.gov (United States)

    Kim, Heegon; Lee, Junsung; Oh, Chanhee; Park, Ji-Ho

    2017-06-01

    The targeted delivery of therapeutics using antibodies or nanomaterials has improved the precision and safety of cancer therapy. However, the paucity and heterogeneity of identified molecular targets within tumours have resulted in poor and uneven distribution of targeted agents, thus compromising treatment outcomes. Here, we construct a cooperative targeting system in which synthetic and biological nanocomponents participate together in the tumour cell membrane-selective localization of synthetic receptor-lipid conjugates (SR-lipids) to amplify the subsequent targeting of therapeutics. The SR-lipids are first delivered selectively to tumour cell membranes in the perivascular region using fusogenic liposomes. By hitchhiking with extracellular vesicles secreted by the cells, the SR-lipids are transferred to neighbouring cells and further spread throughout the tumour tissues where the molecular targets are limited. We show that this tumour cell membrane-targeted delivery of SR-lipids leads to uniform distribution and enhanced phototherapeutic efficacy of the targeted photosensitizer.

  18. Collective Action Problem in Heterogeneous Groups with Punishment and Foresight

    Science.gov (United States)

    Perry, Logan; Shrestha, Mahendra Duwal; Vose, Michael D.; Gavrilets, Sergey

    2018-03-01

    The collective action problem can easily undermine cooperation in groups. Recent work has shown that within-group heterogeneity can under some conditions promote voluntary provisioning of collective goods. Here we generalize this work for the case when individuals can not only contribute to the production of collective goods, but also punish free-riders. To do this, we extend the standard theory by allowing individuals to have limited foresight so they can anticipate actions of their group-mates. For humans, this is a realistic assumption because we possess a "theory of mind". We use agent-based simulations to study collective actions that aim to overcome challenges from nature or win competition with neighboring groups. We contrast the dynamics of collective action in egalitarian and hierarchical groups. We show that foresight allows groups to overcome both the first- and second-order free-rider problems. While foresight increases cooperation, it does not necessarily result in higher payoffs. We show that while between-group conflicts promotes within-group cooperation, the effects of cultural group selection on cooperation are relatively small. Our models predict the emergence of a division of labor in which more powerful individuals specialize in punishment while less powerful individuals mostly contribute to the production of collective goods.

  19. Heterogeneous update mechanisms in evolutionary games: Mixing innovative and imitative dynamics

    Science.gov (United States)

    Amaral, Marco Antonio; Javarone, Marco Alberto

    2018-04-01

    Innovation and evolution are two processes of paramount relevance for social and biological systems. In general, the former allows the introduction of elements of novelty, while the latter is responsible for the motion of a system in its phase space. Often, these processes are strongly related, since an innovation can trigger the evolution, and the latter can provide the optimal conditions for the emergence of innovations. Both processes can be studied by using the framework of evolutionary game theory, where evolution constitutes an intrinsic mechanism. At the same time, the concept of innovation requires an opportune mathematical representation. Notably, innovation can be modeled as a strategy, or it can constitute the underlying mechanism that allows agents to change strategy. Here, we analyze the second case, investigating the behavior of a heterogeneous population, composed of imitative and innovative agents. Imitative agents change strategy only by imitating that of their neighbors, whereas innovative ones change strategy without the need for a copying source. The proposed model is analyzed by means of analytical calculations and numerical simulations in different topologies. Remarkably, results indicate that the mixing of mechanisms can be detrimental to cooperation near phase transitions. In those regions, the spatial reciprocity from imitative mechanisms is destroyed by innovative agents, leading to the downfall of cooperation. Our investigation sheds some light on the complex dynamics emerging from the heterogeneity of strategy revision methods, highlighting the role of innovation in evolutionary games.

  20. Fairness in multi-agent systems

    NARCIS (Netherlands)

    Jong, de S.; Tuyls, K.P.; Verbeeck, K.

    2008-01-01

    Multi-agent systems are complex systems in which multiple autonomous entities, called agents, cooperate in order to achieve a common or personal goal. These entities may be computer software, robots, and also humans. In fact, many multi-agent systems are intended to operate in cooperation with or as

  1. International cooperation

    International Nuclear Information System (INIS)

    Prieto, F.E.

    1984-01-01

    It looks doubtless that the need for an international cooperation to solve the worldwide energy problems is already a concern of individuals, institutions, and governments. This is an improvement. But there is something lacking. The author refers to the Atoms for Peace speech, the origin of the IAEA and of the subsequent spreading of the nuclear option. He also refers back to the call made by the Mexican government for a worldwide energy cooperation. He stresses the need for governments to cooperate, so that this international cooperation on energy can be put into operation for the benefit of mankind

  2. Graphene Oxide/Ag Nanoparticles Cooperated with Simvastatin as a High Sensitive X-Ray Computed Tomography Imaging Agent for Diagnosis of Renal Dysfunctions.

    Science.gov (United States)

    Li, Zhan; Tian, Longlong; Liu, Jianli; Qi, Wei; Wu, Qiang; Wang, Haijing; Ali, Mohammad Chand; Wu, Wangsuo; Qiu, Hongdeng

    2017-09-01

    Graphene oxides (GO) are attracting much attention in the diagnosis and therapy of the subcutaneous tumor as a novel biomaterial, but its diagnosis to tissue dysfunction is yet to be found. Here, a novel application of GO for diagnosis of renal dysfunction via contrast-enhanced computed tomography (CT) is proposed. In order to serve as contrast-enhanced agent, Ag nanoparticles (AgNPs) are composited on the surface of GO to promote its X-ray absorption, and then simvastatin is coinjected for eliminating in vivo toxicity induced by AgNPs. It is found that GO/AgNPs can enhance the imaging of CT into the lung, liver, and kidney of mice for a long circulation time (≈24 h) and a safety profile in vivo in the presence of simvastatin. Interestingly, the lower dose of GO/AgNPs (≈0.5 mg per kg bw) shows an excellent performance for CT imaging of renal perfusion, and visually exhibits the right renal dysfunction in model mice. Hence, this work suggests that graphene nanoparticles will play a vital role for the future medical translational development including drug carrier, biosensing, and disease therapy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Heterogeneous reactors

    International Nuclear Information System (INIS)

    Moura Neto, C. de; Nair, R.P.K.

    1979-08-01

    The microscopic study of a cell is meant for the determination of the infinite multiplication factor of the cell, which is given by the four factor formula: K(infinite) = n(epsilon)pf. The analysis of an homogeneous reactor is similar to that of an heterogeneous reactor, but each factor of the four factor formula can not be calculated by the formulas developed in the case of an homogeneous reactor. A great number of methods was developed for the calculation of heterogeneous reactors and some of them are discussed. (Author) [pt

  4. Cooperation in human-computer communication

    OpenAIRE

    Kronenberg, Susanne

    2000-01-01

    The goal of this thesis is to simulate cooperation in human-computer communication to model the communicative interaction process of agents in natural dialogs in order to provide advanced human-computer interaction in that coherence is maintained between contributions of both agents, i.e. the human user and the computer. This thesis contributes to certain aspects of understanding and generation and their interaction in the German language. In spontaneous dialogs agents cooperate by the pro...

  5. International cooperation

    International Nuclear Information System (INIS)

    1996-01-01

    In 1995, Nuclear Regulatory Authority of the Slovak Republic (NRA SR) ensured foreign cooperation particularly in the frame of the Slovak Republic is membership in the IAEA, as well as cooperation with the Nuclear Energy Agency of the Organization for Economic Cooperation and Development (OECD NEA), cooperation with European Union in the frame of PHARE programmes, and intergovernmental cooperation and cooperation among nuclear regulatory authorities. With respect to an international importance, prestige and a wide-scope possibilities of a technical assistance , either a direct one (expert assessments, technology supplies, work placement, scientific trips, training courses) or indirect one (participation at various conferences, seminars, technical committees, etc), the most important cooperation with the IAEA in Vienna. In 1994, the Slovak Republic, was elected to the Board Governors, the represent the group of Eastern European countries. The Slovak Government entrusted the NRA SR's Chairman with representing the Slovak Republic in the Board of Governors. Owing to a good name of Slovakia was elected to the one of two Vice-Chairmen of the Board of Governors at the 882-nd session on the Board. IAEA approved and developed 8 national projects for Slovakia in 1995. Generally, IAEA is contracting scientific contracts with research institutes, nuclear power plants and other organizations. Slovak organizations used these contracts as complementary funding of their tasks. In 1995, there were 12 scientific contracts in progress, or approved respectively. Other international activities of the NRA SR, international co-operations as well as foreign affairs are reported

  6. Competition, cooperation, and corporate culture

    NARCIS (Netherlands)

    Kosfeld, M.; von Siemens, F.A.

    2011-01-01

    Cooperation between workers can be of substantial value to a firm, yet its level often varies substantially between firms. We show that these differences can unfold in a competitive labor market if workers have heterogeneous social preferences and preferences are private information. In our model,

  7. 7 CFR 1124.11 - Cooperative reserve supply unit.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Cooperative reserve supply unit. 1124.11 Section 1124... MARKETING AREA Order Regulating Handling Definitions § 1124.11 Cooperative reserve supply unit. Cooperative reserve supply unit means any cooperative association or its agent that is a handler pursuant to § 1000.9...

  8. Interest rate rules and macroeconomic stability under heterogeneous expectations

    NARCIS (Netherlands)

    Anufriev, M.; Assenza, T.; Hommes, C.; Massaro, D.

    2009-01-01

    The recent macroeconomic literature stresses the importance of managing heterogeneous expectations in the formulation of monetary policy. We use a stylized macro model of Howitt (1992) to investigate inflation dynamics under alternative interest rate rules when agents have heterogeneous expectations

  9. Heterogeneous Gossip

    Science.gov (United States)

    Frey, Davide; Guerraoui, Rachid; Kermarrec, Anne-Marie; Koldehofe, Boris; Mogensen, Martin; Monod, Maxime; Quéma, Vivien

    Gossip-based information dissemination protocols are considered easy to deploy, scalable and resilient to network dynamics. Load-balancing is inherent in these protocols as the dissemination work is evenly spread among all nodes. Yet, large-scale distributed systems are usually heterogeneous with respect to network capabilities such as bandwidth. In practice, a blind load-balancing strategy might significantly hamper the performance of the gossip dissemination.

  10. Cooperative Localization for Mobile Networks

    DEFF Research Database (Denmark)

    Cakmak, Burak; Urup, Daniel Nygaard; Meyer, Florian

    2016-01-01

    We propose a hybrid message passing method for distributed cooperative localization and tracking of mobile agents. Belief propagation and mean field message passing are employed for, respectively, the motion-related and measurementrelated part of the factor graph. Using a Gaussian belief approxim......We propose a hybrid message passing method for distributed cooperative localization and tracking of mobile agents. Belief propagation and mean field message passing are employed for, respectively, the motion-related and measurementrelated part of the factor graph. Using a Gaussian belief...

  11. Design and simulation of material-integrated distributed sensor processing with a code-based agent platform and mobile multi-agent systems.

    Science.gov (United States)

    Bosse, Stefan

    2015-02-16

    Multi-agent systems (MAS) can be used for decentralized and self-organizing data processing in a distributed system, like a resource-constrained sensor network, enabling distributed information extraction, for example, based on pattern recognition and self-organization, by decomposing complex tasks in simpler cooperative agents. Reliable MAS-based data processing approaches can aid the material-integration of structural-monitoring applications, with agent processing platforms scaled to the microchip level. The agent behavior, based on a dynamic activity-transition graph (ATG) model, is implemented with program code storing the control and the data state of an agent, which is novel. The program code can be modified by the agent itself using code morphing techniques and is capable of migrating in the network between nodes. The program code is a self-contained unit (a container) and embeds the agent data, the initialization instructions and the ATG behavior implementation. The microchip agent processing platform used for the execution of the agent code is a standalone multi-core stack machine with a zero-operand instruction format, leading to a small-sized agent program code, low system complexity and high system performance. The agent processing is token-queue-based, similar to Petri-nets. The agent platform can be implemented in software, too, offering compatibility at the operational and code level, supporting agent processing in strong heterogeneous networks. In this work, the agent platform embedded in a large-scale distributed sensor network is simulated at the architectural level by using agent-based simulation techniques.

  12. Design and Simulation of Material-Integrated Distributed Sensor Processing with a Code-Based Agent Platform and Mobile Multi-Agent Systems

    Directory of Open Access Journals (Sweden)

    Stefan Bosse

    2015-02-01

    Full Text Available Multi-agent systems (MAS can be used for decentralized and self-organizing data processing in a distributed system, like a resource-constrained sensor network, enabling distributed information extraction, for example, based on pattern recognition and self-organization, by decomposing complex tasks in simpler cooperative agents. Reliable MAS-based data processing approaches can aid the material-integration of structural-monitoring applications, with agent processing platforms scaled to the microchip level. The agent behavior, based on a dynamic activity-transition graph (ATG model, is implemented with program code storing the control and the data state of an agent, which is novel. The program code can be modified by the agent itself using code morphing techniques and is capable of migrating in the network between nodes. The program code is a self-contained unit (a container and embeds the agent data, the initialization instructions and the ATG behavior implementation. The microchip agent processing platform used for the execution of the agent code is a standalone multi-core stack machine with a zero-operand instruction format, leading to a small-sized agent program code, low system complexity and high system performance. The agent processing is token-queue-based, similar to Petri-nets. The agent platform can be implemented in software, too, offering compatibility at the operational and code level, supporting agent processing in strong heterogeneous networks. In this work, the agent platform embedded in a large-scale distributed sensor network is simulated at the architectural level by using agent-based simulation techniques.

  13. An agent-based model of signal transduction in bacterial chemotaxis.

    Directory of Open Access Journals (Sweden)

    Jameson Miller

    2010-05-01

    Full Text Available We report the application of agent-based modeling to examine the signal transduction network and receptor arrays for chemotaxis in Escherichia coli, which are responsible for regulating swimming behavior in response to environmental stimuli. Agent-based modeling is a stochastic and bottom-up approach, where individual components of the modeled system are explicitly represented, and bulk properties emerge from their movement and interactions. We present the Chemoscape model: a collection of agents representing both fixed membrane-embedded and mobile cytoplasmic proteins, each governed by a set of rules representing knowledge or hypotheses about their function. When the agents were placed in a simulated cellular space and then allowed to move and interact stochastically, the model exhibited many properties similar to the biological system including adaptation, high signal gain, and wide dynamic range. We found the agent based modeling approach to be both powerful and intuitive for testing hypotheses about biological properties such as self-assembly, the non-linear dynamics that occur through cooperative protein interactions, and non-uniform distributions of proteins in the cell. We applied the model to explore the role of receptor type, geometry and cooperativity in the signal gain and dynamic range of the chemotactic response to environmental stimuli. The model provided substantial qualitative evidence that the dynamic range of chemotactic response can be traced to both the heterogeneity of receptor types present, and the modulation of their cooperativity by their methylation state.

  14. An agent-based model of signal transduction in bacterial chemotaxis.

    Science.gov (United States)

    Miller, Jameson; Parker, Miles; Bourret, Robert B; Giddings, Morgan C

    2010-05-13

    We report the application of agent-based modeling to examine the signal transduction network and receptor arrays for chemotaxis in Escherichia coli, which are responsible for regulating swimming behavior in response to environmental stimuli. Agent-based modeling is a stochastic and bottom-up approach, where individual components of the modeled system are explicitly represented, and bulk properties emerge from their movement and interactions. We present the Chemoscape model: a collection of agents representing both fixed membrane-embedded and mobile cytoplasmic proteins, each governed by a set of rules representing knowledge or hypotheses about their function. When the agents were placed in a simulated cellular space and then allowed to move and interact stochastically, the model exhibited many properties similar to the biological system including adaptation, high signal gain, and wide dynamic range. We found the agent based modeling approach to be both powerful and intuitive for testing hypotheses about biological properties such as self-assembly, the non-linear dynamics that occur through cooperative protein interactions, and non-uniform distributions of proteins in the cell. We applied the model to explore the role of receptor type, geometry and cooperativity in the signal gain and dynamic range of the chemotactic response to environmental stimuli. The model provided substantial qualitative evidence that the dynamic range of chemotactic response can be traced to both the heterogeneity of receptor types present, and the modulation of their cooperativity by their methylation state.

  15. Cooperative target convergence using multiple agents

    International Nuclear Information System (INIS)

    Kwok, K.S.; Driessen, B.J.

    1997-01-01

    This work considers the problem of causing multiple (100''s) autonomous mobile robots to converge to a target and provides a follow-the-leader approach to the problem. Each robot has only a limited-range sensor for sending the target and also larger but also limited-range robot-to-robot communication capability. Because of the small amount of information available to the robots, a practical approach to improve convergence to the target is to have a robot follow the robot with the best quality of information. Specifically, each robot emits a signal that informs in-range robots what its status is. A robot has a status value of 0 if it is itself in range of the target. A robot has a status of 1 if it is not in range of the target but is in communication range of a robot that is in range of the target. A robot has a status of 2 if it is not in range of the target but is within range of another robot that has status 1, and so on. Of all the mobile robots that any given robot is in range of, it follows the one with the best status. The emergent behavior is the ant-like trails of robots following each other toward the target. If the robot is not in range of another robot that is either in range of the target or following another robot, the robot will assign-1 to its quality-of-information, and will execute an exhaustive search. The exhaustive search will continue until it encounters either the target or another robot with a nonnegative quality-of-information. The quality of information approach was extended to the case where each robot only has two-bit signals informing it of distance to in-range robots

  16. Coordinating Filtering Strategies in Cooperative Agent Communities

    OpenAIRE

    Milosevic, Dragan

    2006-01-01

    Eine Folge der gegenwärtigen Informationsflut ist, dass die Benutzer die gewünschten Informationen in verschiedenen Quellen suchen müssen. Sie haben dabei große Schwierigkeiten ihr Informationsbedürfnis formal zu beschreiben. Folglich führen selten manuell erstellte Anfragen an ein Suchsystem zu befriedigenden Ergebnissen. Ein kritischer Faktor bei der Suche nach gewünschten Informationen ist die Antwortzeit des Systems, d.h. die Zeitspanne zwischen dem Absenden einer Suchanfrage und der Präs...

  17. Cooperative target convergence using multiple agents

    Energy Technology Data Exchange (ETDEWEB)

    Kwok, K.S.; Driessen, B.J.

    1997-10-01

    This work considers the problem of causing multiple (100`s) autonomous mobile robots to converge to a target and provides a follow-the-leader approach to the problem. Each robot has only a limited-range sensor for sending the target and also larger but also limited-range robot-to-robot communication capability. Because of the small amount of information available to the robots, a practical approach to improve convergence to the target is to have a robot follow the robot with the best quality of information. Specifically, each robot emits a signal that informs in-range robots what its status is. A robot has a status value of 0 if it is itself in range of the target. A robot has a status of 1 if it is not in range of the target but is in communication range of a robot that is in range of the target. A robot has a status of 2 if it is not in range of the target but is within range of another robot that has status 1, and so on. Of all the mobile robots that any given robot is in range of, it follows the one with the best status. The emergent behavior is the ant-like trails of robots following each other toward the target. If the robot is not in range of another robot that is either in range of the target or following another robot, the robot will assign-1 to its quality-of-information, and will execute an exhaustive search. The exhaustive search will continue until it encounters either the target or another robot with a nonnegative quality-of-information. The quality of information approach was extended to the case where each robot only has two-bit signals informing it of distance to in-range robots.

  18. Integrating CLIPS applications into heterogeneous distributed systems

    Science.gov (United States)

    Adler, Richard M.

    1991-01-01

    SOCIAL is an advanced, object-oriented development tool for integrating intelligent and conventional applications across heterogeneous hardware and software platforms. SOCIAL defines a family of 'wrapper' objects called agents, which incorporate predefined capabilities for distributed communication and control. Developers embed applications within agents and establish interactions between distributed agents via non-intrusive message-based interfaces. This paper describes a predefined SOCIAL agent that is specialized for integrating C Language Integrated Production System (CLIPS)-based applications. The agent's high-level Application Programming Interface supports bidirectional flow of data, knowledge, and commands to other agents, enabling CLIPS applications to initiate interactions autonomously, and respond to requests and results from heterogeneous remote systems. The design and operation of CLIPS agents are illustrated with two distributed applications that integrate CLIPS-based expert systems with other intelligent systems for isolating and mapping problems in the Space Shuttle Launch Processing System at the NASA Kennedy Space Center.

  19. Agent-Based Optimization

    CERN Document Server

    Jędrzejowicz, Piotr; Kacprzyk, Janusz

    2013-01-01

    This volume presents a collection of original research works by leading specialists focusing on novel and promising approaches in which the multi-agent system paradigm is used to support, enhance or replace traditional approaches to solving difficult optimization problems. The editors have invited several well-known specialists to present their solutions, tools, and models falling under the common denominator of the agent-based optimization. The book consists of eight chapters covering examples of application of the multi-agent paradigm and respective customized tools to solve  difficult optimization problems arising in different areas such as machine learning, scheduling, transportation and, more generally, distributed and cooperative problem solving.

  20. Inequity aversion and the evolution of cooperation

    OpenAIRE

    Ahmed, Asrar; Karlapalem, Kamalakar

    2014-01-01

    Evolution of cooperation is a widely studied problem in biology, social science, economics, and artificial intelligence. Most of the existing approaches that explain cooperation rely on some notion of direct or indirect reciprocity. These reciprocity based models assume agents recognize their partner and know their previous interactions, which requires advanced cognitive abilities. In this paper we are interested in developing a model that produces cooperation without requiring any explicit m...

  1. Interorganizational Cooperation

    Science.gov (United States)

    2016-10-12

    Administrative Services Officer , Office of Congressional and Intergovernmental Affairs, Office of the Chief Financial Officer , Office of the Chief ...Nations. • Clarifies the role of the United States Agency for International Development (USAID) Office of Transition Initiatives and its relationship...Centralize interorganizational cooperation within the command group. Under this model, the chief of staff or a special staff officer within the command

  2. Evolving Self-Organized Behavior for Homogeneous and Heterogeneous UAV or UCAV Swarms

    National Research Council Canada - National Science Library

    Price, Ian C

    2006-01-01

    This investigation uses a self-organization (SO) approach to enable cooperative search and destruction of retaliating targets with swarms of homogeneous and heterogeneous unmanned aerial vehicles (UAVs...

  3. Multimodal training between agents

    DEFF Research Database (Denmark)

    Rehm, Matthias

    2003-01-01

    In the system Locator1, agents are treated as individual and autonomous subjects that are able to adapt to heterogenous user groups. Applying multimodal information from their surroundings (visual and linguistic), they acquire the necessary concepts for a successful interaction. This approach has...

  4. Artificial agents learning human fairness

    NARCIS (Netherlands)

    Jong, de S.; Tuyls, K.P.; Verbeeck, K.; Padgham, xx; Parkes, xx

    2008-01-01

    Recent advances in technology allow multi-agent systems to be deployed in cooperation with or as a service for humans. Typically, those systems are designed assuming individually rational agents, according to the principles of classical game theory. However, research in the field of behavioral

  5. Effect of initial fraction of cooperators on cooperative behavior in evolutionary prisoner's dilemma game.

    Directory of Open Access Journals (Sweden)

    Keizo Shigaki

    Full Text Available We investigate the influence of initial fraction of cooperators on the evolution of cooperation in spatial prisoner's dilemma games. Compared with the results of heterogeneous networks, we find that there is a relatively low initial fraction of cooperators to guarantee higher equilibrium cooperative level. While this interesting phenomenon is contrary to the commonly shared knowledge that higher initial fraction of cooperators can provide better environment for the evolution of cooperation. To support our outcome, we explore the time courses of cooperation and find that the whole course can be divided into two sequent stages: enduring (END and expanding (EXP periods. At the end of END period, thought there is a limited number of cooperator clusters left for the case of low initial setup, these clusters can smoothly expand to hold the whole system in the EXP period. However, for high initial fraction of cooperators, superfluous cooperator clusters hinder their effective expansion, which induces many remaining defectors surrounding the cooperator clusters. Moreover, through intensive analysis, we also demonstrate that when the tendency of three cooperation cluster characteristics (cluster size, cluster number and cluster shape are consistent within END and EXP periods, the state that maximizes cooperation can be favored.

  6. Cooperation enhanced by the coevolution of teaching activity in evolutionary prisoner's dilemma games with voluntary participation.

    Directory of Open Access Journals (Sweden)

    Chen Shen

    Full Text Available Voluntary participation, as an additional strategy involved in repeated games, has been proved to be an efficient way to promote the evolution of cooperation theoretically and empirically. Besides, current studies show that the coevolution of teaching activity can promote cooperation. Thus, inspired by aforementioned above, we investigate the effect of coevolution of teaching activity on the evolution of cooperation for prisoner's dilemma game with voluntary participation: when the focal player successfully enforces its strategy on the opponent, his teaching ability will get an increase. Through numerical simulation, we have shown that voluntary participation could effectively promote the fraction of cooperation, which is also affected by the value of increment. Furthermore, we investigate the influence of the increment value on the density of different strategies and find that there exists an optimal increment value that plays an utmost role on the evolutionary dynamics. With regard to this observation, we unveil that an optimal value of increment can lead to strongest heterogeneity in agents' teaching ability, further promoting the evolution of cooperation.

  7. Cooperation enhanced by the coevolution of teaching activity in evolutionary prisoner's dilemma games with voluntary participation.

    Science.gov (United States)

    Shen, Chen; Chu, Chen; Geng, Yini; Jin, Jiahua; Chen, Fei; Shi, Lei

    2018-01-01

    Voluntary participation, as an additional strategy involved in repeated games, has been proved to be an efficient way to promote the evolution of cooperation theoretically and empirically. Besides, current studies show that the coevolution of teaching activity can promote cooperation. Thus, inspired by aforementioned above, we investigate the effect of coevolution of teaching activity on the evolution of cooperation for prisoner's dilemma game with voluntary participation: when the focal player successfully enforces its strategy on the opponent, his teaching ability will get an increase. Through numerical simulation, we have shown that voluntary participation could effectively promote the fraction of cooperation, which is also affected by the value of increment. Furthermore, we investigate the influence of the increment value on the density of different strategies and find that there exists an optimal increment value that plays an utmost role on the evolutionary dynamics. With regard to this observation, we unveil that an optimal value of increment can lead to strongest heterogeneity in agents' teaching ability, further promoting the evolution of cooperation.

  8. Link prediction based on nonequilibrium cooperation effect

    Science.gov (United States)

    Li, Lanxi; Zhu, Xuzhen; Tian, Hui

    2018-04-01

    Link prediction in complex networks has become a common focus of many researchers. But most existing methods concentrate on neighbors, and rarely consider degree heterogeneity of two endpoints. Node degree represents the importance or status of endpoints. We describe the large-degree heterogeneity as the nonequilibrium between nodes. This nonequilibrium facilitates a stable cooperation between endpoints, so that two endpoints with large-degree heterogeneity tend to connect stably. We name such a phenomenon as the nonequilibrium cooperation effect. Therefore, this paper proposes a link prediction method based on the nonequilibrium cooperation effect to improve accuracy. Theoretical analysis will be processed in advance, and at the end, experiments will be performed in 12 real-world networks to compare the mainstream methods with our indices in the network through numerical analysis.

  9. Cooperative Cloudlet for Pervasive Networks

    Directory of Open Access Journals (Sweden)

    Tauseef Jamal

    2017-05-01

    Full Text Available The notion of cooperation in wireless communication has got significant attention from both academia and industrial persons towards to address the performance drawbacks of wireless sensor network due to reason of user’s high mobility and lack of resources of network. The future wireless systems should be highly heterogeneous and interconnected because motivating cooperative relaying has to apply on the future mobile network for efficient results and future demand. As currently the mobile computing is facing latency and battery drainage issues which need to address and solve hence in this work we are proposed mobile - centric and opportunistic communication architecture. In this work mobile devices which are in the range of Wi - Fi of each other can create cluste r with each other and can create an ad - hoc cooperative cloud using Relay Spot[1 - 4]. The Collaboration between these devices can enable them to resourcefully use the augmentation without any infrastructure.

  10. Transshipment games with identical newsvendors and cooperation costs

    NARCIS (Netherlands)

    Hezarkhani, B.; Kubiak, W.

    2013-01-01

    In a transshipment game, supply chain agents cooperate to transship surplus products. Although the game has been well studied in the OR literature, the fundamental question whether the agents can afford cooperation costs to set up and maintain the game in the first place has not been addressed thus

  11. Transboundary cooperation

    International Nuclear Information System (INIS)

    Rauber, D.

    2006-01-01

    The operation of nuclear power plants near national borders requires a close bilateral co-operation to cope with accidents having off-site radiological impacts. For example in 1978 such an agreement was signed by the German and Swiss government. The accident at the Chernobyl NPP changed the international co-operation in the framework of international consequence management. International conventions were agreed to insure a timely notification and international assistance in case of an accident with transboundary effects. In order to fulfill these conventions several procedures were introduced. In addition, bilateral agreements were signed also with countries which are not operating nuclear power plants near national borders. Since then no accident took place that would have required any notification. However, following the experience the expectations to these networks have changed considerably and hence sustainable development is required to cope with new challenges such as long term consequences management, new radiological threats, faster international assistance, media and public concerns, and technical evolution of communications systems. (author)

  12. Costly advertising and the evolution of cooperation

    OpenAIRE

    Brede, Markus

    2013-01-01

    In this paper, I investigate the co-evolution of fast and slow strategy spread and game strategies in populations of spatially distributed agents engaged in a one off evolutionary dilemma game. Agents are characterized by a pair of traits, a game strategy (cooperate or defect) and a binary 'advertising' strategy (advertise or don't advertise). Advertising, which comes at a cost [Formula: see text], allows investment into faster propagation of the agents' traits to adjacent individuals. Import...

  13. Biological Agents

    Science.gov (United States)

    ... E-Tools Safety and Health Topics / Biological Agents Biological Agents This page requires that javascript be enabled ... 202) 693-2300 if additional assistance is required. Biological Agents Menu Overview In Focus: Ebola Frederick A. ...

  14. Fostering cooperative activism through critical design

    DEFF Research Database (Denmark)

    Menendez Blanco, Maria; Bjørn, Pernille; De Angeli, Antonella

    2017-01-01

    Critical design is gaining momentum in interaction design, yet little CSCW research has focused on articulating the cooperative potentials of critical design artefacts. We address this gap by reflecting upon a design project aimed at overturning the prevailing narrative regarding dyslexia in Italy....... The adversarial propositions embedded in our critical design artefacts challenged the description of dyslexia as a learning disorder putting forward the view of a learning difference. These artefacts demonstrated their capacity to bridge heterogeneous social worlds (those of teachers, children, and parents......) into one cooperative entity and mobilise cooperative activism. The contribution to CSCW is two-fold. Firstly, we introduce the cooperative potentials of critical design artefacts; secondly, we propose critical design as a strategy for researchers engaging with cooperative activism....

  15. Automatic Generation of Agents using Reusable Soft Computing Code Libraries to develop Multi Agent System for Healthcare

    OpenAIRE

    Priti Srinivas Sajja

    2015-01-01

    This paper illustrates architecture for a multi agent system in healthcare domain. The architecture is generic and designed in form of multiple layers. One of the layers of the architecture contains many proactive, co-operative and intelligent agents such as resource management agent, query agent, pattern detection agent and patient management agent. Another layer of the architecture is a collection of libraries to auto-generate code for agents using soft computing techni...

  16. Emergence of cooperation in non-scale-free networks

    International Nuclear Information System (INIS)

    Zhang, Yichao; Aziz-Alaoui, M A; Bertelle, Cyrille; Zhou, Shi; Wang, Wenting

    2014-01-01

    Evolutionary game theory is one of the key paradigms behind many scientific disciplines from science to engineering. Previous studies proposed a strategy updating mechanism, which successfully demonstrated that the scale-free network can provide a framework for the emergence of cooperation. Instead, individuals in random graphs and small-world networks do not favor cooperation under this updating rule. However, a recent empirical result shows the heterogeneous networks do not promote cooperation when humans play a prisoner’s dilemma. In this paper, we propose a strategy updating rule with payoff memory. We observe that the random graphs and small-world networks can provide even better frameworks for cooperation than the scale-free networks in this scenario. Our observations suggest that the degree heterogeneity may be neither a sufficient condition nor a necessary condition for the widespread cooperation in complex networks. Also, the topological structures are not sufficed to determine the level of cooperation in complex networks. (paper)

  17. 混有协同自适应巡航控制车辆的异质交通流稳定性解析与基本图模型%Stability analysis and fundamental diagram of heterogeneous traffic flow mixed with cooperative adaptive cruise control vehicles

    Institute of Scientific and Technical Information of China (English)

    秦严严; 王昊; 王炜; 万千

    2017-01-01

    This paper is aimed at building a framework for string stability analysis of traffic flow mixed with different coop-erative adaptive cruise control (CACC) market penetration rates. In addition to the string stability, the fundamental diagram of the mixed flow is also taken into consideration for evaluating the effect of CACC vehicles on capacity. In order to describe the car-following dynamics of real CACC vehicles, the CACC model proposed by PATH is employed, which is validated by real experimental data. The intelligent driver model (IDM) is used as a surrogate car-following model for traditional manual driven vehicles. Based on the guidelines proposed by Ward [Ward J A 2009 P h. D. Dissertation (Bristol: University of Bristol)], a framework is developed for the analytical investigation of het-erogeneous traffic flow string stability. The framework presented considers the instability condition of traffic flow as a linear function of CACC market penetration rate. Following the framework, the string stabilities of the mixed traffic flow under different CACC market penetration rates and equilibrium velocities are analyzed. For fundamental diagram of the heterogeneous traffic flow, the equilibrium velocity-spacing functions of manual vehicles and CACC vehicles are obtained respectively based on car-following model. Then, the fundamental diagram of the density-velocity relationship of the heterogeneous traffic flow is derived based on the definition of trac flow density. In addition, the theoretical fundamental diagram is plotted to show the property of traffic throughput. The numerical simulations are also carried out in order to investigate the effect of CACC vehicle on the characteristics of fundamental diagram. Besides, sensitivity analyses on CACC desired time gap are conducted for both string stability and fundamental diagram. Analytical studies and simulation results are as follows. 1) The heterogeneous traffic flow is stable for different equilibrium velocities

  18. Cationic Zn-Porphyrin Polymer Coated onto CNTs as a Cooperative Catalyst for the Synthesis of Cyclic Carbonates.

    Science.gov (United States)

    Jayakumar, Sanjeevi; Li, He; Chen, Jian; Yang, Qihua

    2018-01-24

    The development of solid catalysts containing multiple active sites that work cooperatively is very attractive for biomimetic catalysis. Herein, we report the synthesis of bifunctional catalysts by supporting cationic porphyrin-based polymers on carbon nanotubes (CNTs) using the direct reaction of 5,10,15,20-tetrakis(4-pyridyl)porphyrin zinc(II), di(1H-imidazol-1-yl)methane, and 1,4-bis(bromomethyl)benzene in the presence of CNTs. The bifunctional catalysts could efficiently catalyze the cycloaddition reaction of epoxides and CO 2 under solvent-free conditions with porphyrin zinc(II) as the Lewis acid site and a bromine anion as a nucleophilic agent working in a cooperative way. Furthermore, a relative amount of porphyrin zinc(II) and quaternary ammonium bromide could be facilely adjusted for facilitating cooperative behavior. The bifunctional catalyst with a TOF up to 2602 h -1 is much more active than the corresponding homogeneous counterpart and is one of the most active heterogeneous catalysts ever reported under cocatalyst-free conditions. The high activity is mainly attributed to the enhanced cooperation effect of the bifunctional catalyst. With a wide substrate scope, the bifunctional catalyst could be stably recycled. This work demonstrates a new approach for the generation of a cooperative activation effect for solid catalysts.

  19. Researches on Agricultural Cooperative Economic Organization Promoting Agricultural Insurance Development

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The advantages of cooperative economic organization being the effective carrier of agricultural insurance development are analyzed. Firstly, cooperative economic organization promotes scale management and solves the problem of decentralized operation of small households. Secondly, cooperative economic organization can settle the problem of peasants’ low systematization. Thirdly, cooperative economic organization can largely reduce the costs of agricultural insurance operation. Fourthly, cooperative organization decreases moral risks as well as adverse selection to some extent. Lastly, cooperative organization, to a certain degree, reduces the risks of agricultural production and increases the insurability of agricultural risks. Meanwhile, limitations of agricultural cooperative economic organization being the carrier of agricultural insurance operation are pointed out. Firstly, cooperative economic organization has limited coverage and small size of organization, which is harmful to the diversification of agricultural risks. Secondly, cooperative economic organization lacks capital funds and its development is not standard, which is not perfect for the function exertion as a carrier. Lastly, members of professional cooperative organization have low cultural qualities, which restrict the implementation of agricultural insurance. The modes of farmers’ cooperative economic organization promoting agricultural insurance development are proposed, including mode of agricultural insurance cooperative ( mutual corporation), mode of "leading enterprises (companies) + professional cooperative organization (planting majors) + insurance" and mode of professional cooperatives serving as agricultural insurance agent. Last of all, the promoting role of agricultural insurance in agricultural cooperative economic organization is briefly illustrated.

  20. Evolutionary Game Theory-Based Evaluation of P2P File-Sharing Systems in Heterogeneous Environments

    Directory of Open Access Journals (Sweden)

    Yusuke Matsuda

    2010-01-01

    Full Text Available Peer-to-Peer (P2P file sharing is one of key technologies for achieving attractive P2P multimedia social networking. In P2P file-sharing systems, file availability is improved by cooperative users who cache and share files. Note that file caching carries costs such as storage consumption and processing load. In addition, users have different degrees of cooperativity in file caching and they are in different surrounding environments arising from the topological structure of P2P networks. With evolutionary game theory, this paper evaluates the performance of P2P file sharing systems in such heterogeneous environments. Using micro-macro dynamics, we analyze the impact of the heterogeneity of user selfishness on the file availability and system stability. Further, through simulation experiments with agent-based dynamics, we reveal how other aspects, for example, synchronization among nodes and topological structure, affect the system performance. Both analytical and simulation results show that the environmental heterogeneity contributes to the file availability and system stability.

  1. Emergence of heterogeneity and political organization in information exchange networks.

    Science.gov (United States)

    Guttenberg, Nicholas; Goldenfeld, Nigel

    2010-04-01

    We present a simple model of the emergence of the division of labor and the development of a system of resource subsidy from an agent-based model of directed resource production with variable degrees of trust between the agents. The model has three distinct phases corresponding to different forms of societal organization: disconnected (independent agents), homogeneous cooperative (collective state), and inhomogeneous cooperative (collective state with a leader). Our results indicate that such levels of organization arise generically as a collective effect from interacting agent dynamics and may have applications in a variety of systems including social insects and microbial communities.

  2. Modelling Cooperative Tumorigenesis in Drosophila

    Science.gov (United States)

    2018-01-01

    The development of human metastatic cancer is a multistep process, involving the acquisition of several genetic mutations, tumour heterogeneity, and interactions with the surrounding microenvironment. Due to the complexity of cancer development in mammals, simpler model organisms, such as the vinegar fly, Drosophila melanogaster, are being utilized to provide novel insights into the molecular mechanisms involved. In this review, we highlight recent advances in modelling tumorigenesis using the Drosophila model, focusing on the cooperation of oncogenes or tumour suppressors, and the interaction of mutant cells with the surrounding tissue in epithelial tumour initiation and progression. PMID:29693007

  3. Modelling Cooperative Tumorigenesis in Drosophila

    Directory of Open Access Journals (Sweden)

    Helena E. Richardson

    2018-01-01

    Full Text Available The development of human metastatic cancer is a multistep process, involving the acquisition of several genetic mutations, tumour heterogeneity, and interactions with the surrounding microenvironment. Due to the complexity of cancer development in mammals, simpler model organisms, such as the vinegar fly, Drosophila melanogaster, are being utilized to provide novel insights into the molecular mechanisms involved. In this review, we highlight recent advances in modelling tumorigenesis using the Drosophila model, focusing on the cooperation of oncogenes or tumour suppressors, and the interaction of mutant cells with the surrounding tissue in epithelial tumour initiation and progression.

  4. Inequity aversion and the evolution of cooperation

    Science.gov (United States)

    Ahmed, Asrar; Karlapalem, Kamalakar

    2014-02-01

    Evolution of cooperation is a widely studied problem in biology, social science, economics, and artificial intelligence. Most of the existing approaches that explain cooperation rely on some notion of direct or indirect reciprocity. These reciprocity based models assume agents recognize their partner and know their previous interactions, which requires advanced cognitive abilities. In this paper we are interested in developing a model that produces cooperation without requiring any explicit memory of previous game plays. Our model is based on the notion of inequity aversion, a concept introduced within behavioral economics, whereby individuals care about payoff equality in outcomes. Here we explore the effect of using income inequality to guide partner selection and interaction. We study our model by considering both the well-mixed and the spatially structured population and present the conditions under which cooperation becomes dominant. Our results support the hypothesis that inequity aversion promotes cooperative relationship among nonkin.

  5. Computational Aspects of Cooperative Game Theory

    CERN Document Server

    Chalkiadakis, Georgios; Wooldridge, Michael

    2011-01-01

    Cooperative game theory is a branch of (micro-)economics that studies the behavior of self-interested agents in strategic settings where binding agreements among agents are possible. Our aim in this book is to present a survey of work on the computational aspects of cooperative game theory. We begin by formally defining transferable utility games in characteristic function form, and introducing key solution concepts such as the core and the Shapley value. We then discuss two major issues that arise when considering such games from a computational perspective: identifying compact representation

  6. South-South Development Cooperation and Soft Power. The case of Brazil's foreign policy and technical cooperation

    DEFF Research Database (Denmark)

    Bry, Sandra

    's participation in development cooperation and how these international political ambitions influence the project model of its South-South Development Cooperation, called technical cooperation. This was done by investigating the manifestations of ‘soft power’ in Brazilian development cooperation activities...... of the agent's attractive actions without which a country's soft power is non-existent. Therefore this thesis maintains that soft power theory should shift its current analytical focus from the agent to the subject and enhance the analysis on the role of subject's perceptions in the creation of ‘soft...

  7. Agent-based enterprise integration

    Energy Technology Data Exchange (ETDEWEB)

    N. M. Berry; C. M. Pancerella

    1998-12-01

    The authors are developing and deploying software agents in an enterprise information architecture such that the agents manage enterprise resources and facilitate user interaction with these resources. The enterprise agents are built on top of a robust software architecture for data exchange and tool integration across heterogeneous hardware and software. The resulting distributed multi-agent system serves as a method of enhancing enterprises in the following ways: providing users with knowledge about enterprise resources and applications; accessing the dynamically changing enterprise; locating enterprise applications and services; and improving search capabilities for applications and data. Furthermore, agents can access non-agents (i.e., databases and tools) through the enterprise framework. The ultimate target of the effort is the user; they are attempting to increase user productivity in the enterprise. This paper describes their design and early implementation and discusses the planned future work.

  8. Heterogeneous expectations in monetary DSGE models

    NARCIS (Netherlands)

    Massaro, D.

    2013-01-01

    This paper derives a general New Keynesian framework with heterogeneous expectations by explicitly solving the micro-foundations underpinning the model. The resulting reduced form is analytically tractable and encompasses the representative rational agent benchmark as a special case. We specify a

  9. International co-operation

    International Nuclear Information System (INIS)

    1998-01-01

    In this part the are reviewed: Co-operation with IAEA; Participation of the Slovakia on the 41 st session of the General Conference; The comprehensive Nuclear-Test-Ban Treaty Organization; Co-operation with the Organization for Economic Co-operation and Development; co-operation with the European Commission; Fulfillment of obligations resulting from the international contracting documents

  10. Sorting and sustaining cooperation

    DEFF Research Database (Denmark)

    Vikander, Nick

    2013-01-01

    This paper looks at cooperation in teams where some people are selfish and others are conditional cooperators, and where lay-offs will occur at a fixed future date. I show that the best way to sustain cooperation prior to the lay-offs is often in a sorting equilibrium, where conditional cooperators...... can identify and then work with one another. Changes to parameters that would seem to make cooperation more attractive, such as an increase in the discount factor or the fraction of conditional cooperators, can reduce equilibrium cooperation if they decrease a selfish player's incentive to sort....

  11. Vitamin E succinate is a potent novel antineoplastic agent with high selectivity and cooperativity with tumor necrosis factor-related apoptosis-inducing ligand (Apo2 ligand) in vivo

    Czech Academy of Sciences Publication Activity Database

    Weber, T.; Lu, M.; Anděra, Ladislav; Lahm, H.; Gellert, N.; Fariss, M. W.; Kořínek, Vladimír; Sattler, W.; Ucker, D. S.; Terman, A.; Schroder, A.; Erl, W.; Brunk, U. T.; Coffey, R. J.; Weber, C.; Neuzil, J.

    2002-01-01

    Roč. 8, - (2002), s. 863-869 ISSN 1078-0432 R&D Projects: GA ČR GA312/99/0348 Institutional research plan: CEZ:AV0Z5052915 Keywords : Vitamin E, Antineoplastic Agent, Tumor Necrosis Factor Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.991, year: 2002

  12. Intuition, deliberation, and the evolution of cooperation.

    Science.gov (United States)

    Bear, Adam; Rand, David G

    2016-01-26

    Humans often cooperate with strangers, despite the costs involved. A long tradition of theoretical modeling has sought ultimate evolutionary explanations for this seemingly altruistic behavior. More recently, an entirely separate body of experimental work has begun to investigate cooperation's proximate cognitive underpinnings using a dual-process framework: Is deliberative self-control necessary to reign in selfish impulses, or does self-interested deliberation restrain an intuitive desire to cooperate? Integrating these ultimate and proximate approaches, we introduce dual-process cognition into a formal game-theoretic model of the evolution of cooperation. Agents play prisoner's dilemma games, some of which are one-shot and others of which involve reciprocity. They can either respond by using a generalized intuition, which is not sensitive to whether the game is one-shot or reciprocal, or pay a (stochastically varying) cost to deliberate and tailor their strategy to the type of game they are facing. We find that, depending on the level of reciprocity and assortment, selection favors one of two strategies: intuitive defectors who never deliberate, or dual-process agents who intuitively cooperate but sometimes use deliberation to defect in one-shot games. Critically, selection never favors agents who use deliberation to override selfish impulses: Deliberation only serves to undermine cooperation with strangers. Thus, by introducing a formal theoretical framework for exploring cooperation through a dual-process lens, we provide a clear answer regarding the role of deliberation in cooperation based on evolutionary modeling, help to organize a growing body of sometimes-conflicting empirical results, and shed light on the nature of human cognition and social decision making.

  13. Ignorance Is Bliss, But for Whom? The Persistent Effect of Good Will on Cooperation

    Directory of Open Access Journals (Sweden)

    Mike Farjam

    2016-10-01

    Full Text Available Who benefits from the ignorance of others? We address this question from the point of view of a policy maker who can induce some ignorance into a system of agents competing for resources. Evolutionary game theory shows that when unconditional cooperators or ignorant agents compete with defectors in two-strategy settings, unconditional cooperators get exploited and are rendered extinct. In contrast, conditional cooperators, by utilizing some kind of reciprocity, are able to survive and sustain cooperation when competing with defectors. We study how cooperation thrives in a three-strategy setting where there are unconditional cooperators, conditional cooperators and defectors. By means of simulation on various kinds of graphs, we show that conditional cooperators benefit from the existence of unconditional cooperators in the majority of cases. However, in worlds that make cooperation hard to evolve, defectors benefit.

  14. A Secure Protocol Based on a Sedentary Agent for Mobile Agent Environments

    OpenAIRE

    Abdelmorhit E. Rhazi; Samuel Pierre; Hanifa Boucheneb

    2007-01-01

    The main challenge when deploying mobile agent environments pertains to security issues concerning mobile agents and their executive platform. This paper proposes a secure protocol which protects mobile agents against attacks from malicious hosts in these environments. Protection is based on the perfect cooperation of a sedentary agent running inside a trusted third host. Results show that the protocol detects several attacks, such as denial of service, incorrect execution and re-execution of...

  15. To cooperate or not to cooperate

    DEFF Research Database (Denmark)

    Wessels, Josepha Ivanka

    To Cooperate or not to Cooperate...? discusses results of a research project to study the rehabilitation of 1500-year old water tunnels, so called "qanats", in Syria. Communities all over the world are using traditional technologies to extract drinkingwater, irrigate their lands and feed...... their livestock. But these often sustainable and ancient ways to make use of groundwater are in rapid decline worldwide. A research project started in 1999 to study the rehabilitation of 1500-year old water tunnels called "qanats"in Syria. To Cooperate or not to Cooperate...? discusses results and outcomes...

  16. Communication, Cooperation, and Negotiation in Culturally Heterogeneous Groups.

    Science.gov (United States)

    Fiedler, Fred E.; Triandis, Harry C.

    This research program has been concerned with three major subprojects: identifying concepts and behaviors which critically affect intercultural relations; developing principles and methods for programed self-instructional cultural training to help Americans adjust to, and work more effectively in, foreign cultures, or with persons from different…

  17. Heterogeneous aspirations promote cooperation in the prisoner's dilemma game

    OpenAIRE

    Perc, Matjaž; Wang, Zhen

    2017-01-01

    To be the fittest is central to proliferation in evolutionary games. Individuals thus adopt the strategies of better performing players in the hope of successful reproduction. In structured populations the array of those that are eligible to act as strategy sources is bounded to the immediate neighbors of each individual. But which one of these strategy sources should potentially be copied? Previous research dealt with this question either by selecting the fittest or by selecting one player u...

  18. Requirements and Algorithms for Cooperation of Heterogeneous Radio Access Networks

    DEFF Research Database (Denmark)

    Mihovska, Albena D.; Tragos, Elias; Mino, Emilio

    2009-01-01

    systems.The RRM mechanisms are evaluated for the scenario of intra-RAN and inter-RAN user mobility. The RRM framework incorporates as novelty improved triggering mechanisms, a network-controlledmobility management scheme with policy enforcement on different levels in the RANarchitecture, and a distributed...

  19. Profit allocation among rational players in a cooperative game under ...

    Indian Academy of Sciences (India)

    research was carried out in two ways on dynamic coalition formation. .... see in a cooperative business that if an agent participates with low quality product then .... solve this question we further need to develop the theory by some definitions.

  20. [Alkylating agents].

    Science.gov (United States)

    Pourquier, Philippe

    2011-11-01

    With the approval of mechlorethamine by the FDA in 1949 for the treatment of hematologic malignancies, alkylating agents are the oldest class of anticancer agents. Even though their clinical use is far beyond the use of new targeted therapies, they still occupy a major place in specific indications and sometimes represent the unique option for the treatment of refractory diseases. Here, we are reviewing the major classes of alkylating agents and their mechanism of action, with a particular emphasis for the new generations of alkylating agents. As for most of the chemotherapeutic agents used in the clinic, these compounds are derived from natural sources. With a complex but original mechanism of action, they represent new interesting alternatives for the clinicians, especially for tumors that are resistant to conventional DNA damaging agents. We also briefly describe the different strategies that have been or are currently developed to potentiate the use of classical alkylating agents, especially the inhibition of pathways that are involved in the repair of DNA lesions induced by these agents. In this line, the development of PARP inhibitors is a striking example of the recent regain of interest towards the "old" alkylating agents.

  1. Agents Play Mix-game

    Science.gov (United States)

    Gou, Chengling

    In recent years, economics and finance see the shift of paradigm from representative agent models to heterogeneous agent models [1, 2]. More and more economists and physicists made efforts in research on heterogeneous agent models for financial markets. Minority game (MG) proposed by D. Challet, and Y. C. Zhang [3] is an example among such efforts. Challet and Zhang's MG model, together with the original bar model of Arthur, attracts a lot of following studies [4-6]. Given MG's richness and yet underlying simplicity, MG has also received much attention as a financial market model [4]. MG comprises an odd number of agents choosing repeatedly between the options of buying (1) and selling (0) a quantity of a risky asset. The agents continually try to make the minority decision, i.e. buy assets when the majority of other agents are selling, and sell when the majority of other agents are buying. Neil F. Johnson [4, 5] and coworkers extended MG by allowing a variable number of active traders at each timestep— they called their modified game as the Grand Canonical Minority Game (GCMG). GCMG, and to a lesser extent the basic MG itself, can reproduce the stylized facts of financial markets, such as volatility clustering and fat-tail distributions.

  2. Collective Motion in Behaviorally Heterogeneous Systems

    Science.gov (United States)

    Copenhagen, Katherine

    Collective motion is a widespread phenomenon in nature where individuals actively propel themselves, gather together and move as a group. Some examples of collective motion are bird flocks, fish schools, bacteria swarms, cell clusters, and crowds of people. Many models seek to understand the effects of activity in collective systems including things such as environmental disorder, density, and interaction details primarily at infinite size limits and with uniform populations. In this dissertation I investigate the effects of finite sizes and behavioral heterogeneity as it exists in nature. Behavioral heterogeneity can originate from several different sources. Mixed populations of individuals can have inherently different behaviors such as mutant bacteria, injured fish, or agents that prefer individualistic behavior over coordinated motion. Alternatively, agents may modify their own behavior based on some local environmental dependency, such as local substrate, or density. In cases such as mutant cheaters in bacteria or malfunctioning drones in swarms, mixed populations of behaviorally heterogeneous agents can be modelled as arising in the form of aligning and non-aligning agents. When this kind of heterogeneity is introduced, there is a critical carrying capacity of non-aligners above which the system is unable to form a cohesive ordered group. However, if the cohesion of the group is relaxed to allow for fracture, the system will actively sort out non-aligning agents the system will exist at a critical non-aligner fraction. A similar heterogeneity could result in a mixture of high and low noise individuals. In this case there is also a critical carry capacity beyond which the system is unable to reach an ordered state, however the nature of this transition depends on the model details. Agents which are part of an ordered collective may vary their behavior as the group changes environments such as a flock of birds flying into a cloud. Using a unique model of a

  3. Cooperative CEO Identity and Efficient Governance: Member or Outside CEO?

    NARCIS (Netherlands)

    Q.X. Liang (Qiao Xin); G.W.J. Hendrikse (George)

    2012-01-01

    textabstractA principal-agent model is formulated to capture the efficiency of cooperatives with a member CEO and cooperatives with an employed outsider as CEO. Results of the model show that the incentive strength regarding the member CEO is stronger compared to that of the outside CEO in order to

  4. Cooperation prevails when individuals adjust their social ties.

    Directory of Open Access Journals (Sweden)

    Francisco C Santos

    2006-10-01

    Full Text Available Conventional evolutionary game theory predicts that natural selection favours the selfish and strong even though cooperative interactions thrive at all levels of organization in living systems. Recent investigations demonstrated that a limiting factor for the evolution of cooperative interactions is the way in which they are organized, cooperators becoming evolutionarily competitive whenever individuals are constrained to interact with few others along the edges of networks with low average connectivity. Despite this insight, the conundrum of cooperation remains since recent empirical data shows that real networks exhibit typically high average connectivity and associated single-to-broad-scale heterogeneity. Here, a computational model is constructed in which individuals are able to self-organize both their strategy and their social ties throughout evolution, based exclusively on their self-interest. We show that the entangled evolution of individual strategy and network structure constitutes a key mechanism for the sustainability of cooperation in social networks. For a given average connectivity of the population, there is a critical value for the ratio W between the time scales associated with the evolution of strategy and of structure above which cooperators wipe out defectors. Moreover, the emerging social networks exhibit an overall heterogeneity that accounts very well for the diversity of patterns recently found in acquired data on social networks. Finally, heterogeneity is found to become maximal when W reaches its critical value. These results show that simple topological dynamics reflecting the individual capacity for self-organization of social ties can produce realistic networks of high average connectivity with associated single-to-broad-scale heterogeneity. On the other hand, they show that cooperation cannot evolve as a result of "social viscosity" alone in heterogeneous networks with high average connectivity, requiring the

  5. Mobile agent-enabled framework for structuring and building distributed systems on the internet

    Institute of Scientific and Technical Information of China (English)

    CAO Jiannong; ZHOU Jingyang; ZHU Weiwei; LI Xuhui

    2006-01-01

    Mobile agent has shown its promise as a powerful means to complement and enhance existing technology in various application areas. In particular, existing work has demonstrated that MA can simplify the development and improve the performance of certain classes of distributed applications, especially for those running on a wide-area, heterogeneous, and dynamic networking environment like the Internet. In our previous work, we extended the application of MA to the design of distributed control functions, which require the maintenance of logical relationship among and/or coordination of processing entities in a distributed system. A novel framework is presented for structuring and building distributed systems, which use cooperating mobile agents as an aid to carry out coordination and cooperation tasks in distributed systems. The framework has been used for designing various distributed control functions such as load balancing and mutual exclusion in our previous work. In this paper, we use the framework to propose a novel approach to detecting deadlocks in distributed system by using mobile agents, which demonstrates the advantage of being adaptive and flexible of mobile agents. We first describe the MAEDD (Mobile Agent Enabled Deadlock Detection) scheme, in which mobile agents are dispatched to collect and analyze deadlock information distributed across the network sites and, based on the analysis, to detect and resolve deadlocks. Then the design of an adaptive hybrid algorithm derived from the framework is presented. The algorithm can dynamically adapt itself to the changes in system state by using different deadlock detection strategies. The performance of the proposed algorithm has been evaluated using simulations. The results show that the algorithm can outperform existing algorithms that use a fixed deadlock detection strategy.

  6. Traitement de l'hétérogénéité sémantique dans les interactions humain-agent et agent-agent

    OpenAIRE

    Mazuel , Laurent

    2008-01-01

    The main purpose of this thesis is the management of semantic heterogeneity in human-agent and agent-agent interaction. We especially focus on the situation where a software agent, supplied with a knowledge representation model, has to understand requests coming from different interlocutors; either it is a human user or another software agent.Most work in this domain either focus on human-agent interaction or agent-agent interaction. On the contrary, we suggest that it is possible to use a co...

  7. Social imitation versus strategic choice, or consensus versus cooperation, in the networked Prisoner's Dilemma

    Science.gov (United States)

    Vilone, Daniele; Ramasco, José J.; Sánchez, Angel; Miguel, Maxi San

    2014-08-01

    The interplay of social and strategic motivations in human interactions is a largely unexplored topic in collective social phenomena. Whether individuals' decisions are taken in a purely strategic basis or due to social pressure without a rational background crucially influences the model outcome. Here we study a networked Prisoner's Dilemma in which decisions are made either based on the replication of the most successful neighbor's strategy (unconditional imitation) or by pure social imitation following an update rule inspired by the voter model. The main effects of the voter dynamics are an enhancement of the final consensus, i.e., asymptotic states are generally uniform, and a promotion of cooperation in certain regions of the parameter space as compared to the outcome of purely strategic updates. Thus, voter dynamics acts as an interface noise and has a similar effect as a pure random noise; furthermore, its influence is mostly independent of the network heterogeneity. When strategic decisions are made following other update rules such as the replicator or Moran processes, the dynamic mixed state found under unconditional imitation for some parameters disappears, but an increase of cooperation in certain parameter regions is still observed. Comparing our results with recent experiments on the Prisoner's Dilemma, we conclude that such a mixed dynamics may explain moody conditional cooperation among the agents.

  8. A Framework for Organization-Aware Agents

    DEFF Research Database (Denmark)

    Jensen, Andreas Schmidt; Dignum, Virginia; Villadsen, Jørgen

    2017-01-01

    boundaries and work towards the objectives of the organization. In this paper, we present the AORTA reasoning framework and show how it can be integrated into typical BDI-agents. We provide operational semantics that enables agents to make organizational decisions in order to coordinate and cooperate without......’ behavior space and describe the expected behavior of the agents. Assuming an open environment, where agents are developed independently of the Organizational structures, agents need to be able to reason about the structure, so that they can deliberate about their actions and act within the expected...

  9. Cooperation, trust and confidence

    NARCIS (Netherlands)

    Korver, T.; Oeij, P.R.A.; Urze, P.C.G.D.

    2007-01-01

    Environmental complexity may strain cooperative relationships, both within and beyond organizations, for two reasons. First, when complexity implies uncertainty the predictability of change disappears. Secondly, change may and often will entail different estimates of the cooperating partners on the

  10. Cooperative Tagging Center (CTC)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Cooperative Tagging Center (CTC) began as the Cooperative Game Fish Tagging Program (GTP) at Woods Hole Oceanographic Institute (WHOI) in 1954. The GTP was...

  11. Adaptive heterogeneous multi-robot teams

    Energy Technology Data Exchange (ETDEWEB)

    Parker, L.E.

    1998-11-01

    This research addresses the problem of achieving fault tolerant cooperation within small- to medium-sized teams of heterogeneous mobile robots. The author describes a novel behavior-based, fully distributed architecture, called ALLIANCE, that utilizes adaptive action selection to achieve fault tolerant cooperative control in robot missions involving loosely coupled, largely independent tasks. The robots in this architecture possess a variety of high-level functions that they can perform during a mission, and must at all times select an appropriate action based on the requirements of the mission, the activities of other robots, the current environmental conditions, and their own internal states. Since such cooperative teams often work in dynamic and unpredictable environments, the software architecture allows the team members to respond robustly and reliably to unexpected environmental changes and modifications in the robot team that may occur due to mechanical failure, the learning of new skills, or the addition or removal of robots from the team by human intervention. After presenting ALLIANCE, the author describes in detail the experimental results of an implementation of this architecture on a team of physical mobile robots performing a cooperative box pushing demonstration. These experiments illustrate the ability of ALLIANCE to achieve adaptive, fault-tolerant cooperative control amidst dynamic changes in the capabilities of the robot team.

  12. Booms, busts and behavioural heterogeneity in stock prices

    NARCIS (Netherlands)

    Hommes, C.; in 't Veld, D.

    2014-01-01

    The global financial crisis indicated the limitations of representative rational agent models for asset pricing solely based on economic fundamentals. We estimate a simple behavioural heterogeneous agents model with boundedly rational traders in which the fundamental value of the stock prices is

  13. Booms, busts and behavioural heterogeneity in stock prices

    NARCIS (Netherlands)

    Hommes, C.; in 't Veld, D.

    2015-01-01

    We estimate a behavioural heterogeneous agents model with boundedly rational traders who know the fundamental stock price, but disagree about the persistence of deviations from the fundamental. Some agents (fundamentalists) believe in mean-reversion of stock prices, while others (chartists) expect a

  14. Booms, busts and behavioural heterogeneity in stock prices

    NARCIS (Netherlands)

    Hommes, C.; in ‘t Veld, D.

    2017-01-01

    We estimate a behavioural heterogeneous agents model with boundedly rational traders who know the fundamental stock price, but disagree about the persistence of deviations from the fundamental. Some agents (fundamentalists) believe in mean-reversion of stock prices, while others (chartists) expect a

  15. Cooperatives as Entrants

    OpenAIRE

    Richard J. Sexton; Terri A. Sexton

    1987-01-01

    A potential shortcoming of game-theoretic models in industrial organization is their failure to consider consumers as players. We introduce a customer coalition --- a cooperative -- as a potential entrant and compare the cooperative entry threat with that posed by the usual for-profit entrant. We identify four fundamental distinctions between cooperative and for-profit entrants and demonstrate that the strategic interplay between a cooperative and an incumbent firm may differ markedly from th...

  16. Choosing the cooperative option

    Energy Technology Data Exchange (ETDEWEB)

    English, G. (National Rural Electric Cooperative Association (United States))

    1999-06-01

    Cooperatives do not ask to be exempted from the law. They do ask that laws and regulations be designed to allow them to meet the needs of their consumer-owners in accordance with cooperative principles, at a time that the marginal consumers being abandoned by for-profit utilities may be ready to gravitate toward cooperatives. The cooperative principles are worth reviewing because they explain the focus on the consumer and the cooperative concept of service: cooperatives are voluntary organizations, open to all persons able to use their services and willing to accept the responsibilities of membership; cooperatives are democratic organizations controlled by their members, who actively participate in setting policies and making decisions, the elected representatives are accountable to the membership; members contribute equitably to, and democratically control, the capital of their cooperative; cooperatives are autonomous, self-help organizations controlled by their members, if they enter into agreements with other organizations, including governments, they do so on terms that ensure democratic control by their members and maintain their cooperative autonomy; cooperatives provide education and training for their members, elected representatives, managers, and employees so they can contribute effectively to the development of their cooperatives, they inform the general public, particularly young people and opinion leaders, about the nature and benefits of cooperation; cooperatives serve their members most effectively and strength the cooperative movement by working together through local, national, regional, and international structures; and while focusing on member needs, cooperatives work for the sustainable development of their communities through policies accepted by their members.

  17. Inertia in Cooperative Remodeling

    OpenAIRE

    Nilsson, Jerker

    1997-01-01

    Which organization model is appropriate for a cooperative enterprise depends on the prerequisites in its business environment. When conditions are changing, the firm must adapt itself. The entry of Sweden, Finland, and Austria into the European Union led to radical changes for agricultural cooperation, especially for Swedish cooperatives since agricultural policy was not allowed a transitional period. After two years, Swedish cooperatives have still not adapted their organization model despit...

  18. What is a cooperative?

    Science.gov (United States)

    Kimberly Zeuli

    2006-01-01

    Groups of individuals throughout time have worked together in pursuit of common goals. The earliest forms of hunting and agriculture required a great deal of cooperation among humans. Although the word "cooperative" can be applied to many different types of group activities, in this publication it refers to a formal business model. Cooperative businesses are...

  19. Three essays in agent-based macroeconomics

    OpenAIRE

    Canzian, Giulia

    2009-01-01

    The dissertation is aimed at offering an insight into the agent-based methodology and its possible application to the macroeconomic analysis. Relying on this methodology, I deal with three different issues concerning heterogeneity of economic agents, bounded rationality and interaction. Specifically, the first chapter is devoted to describe the distinctive characteristics of agent-based economics and its advantages-disadvantages. In the second chapter I propose a credit market framework c...

  20. Designing for cooperation - cooperating in design

    DEFF Research Database (Denmark)

    Kyng, Morten

    1991-01-01

    This article will discuss how to design computer applications that enhance the quality of work and products, and will relate the discussion to current themes in the field of Computer-Supported Cooperative Work (CSCW). Cooperation is a key element of computer use and work practice, yet here...... a specific "CSCW approach is not taken." Instead the focus is cooperation as an important aspect of work that should be integrated into most computer support efforts in order to develop successful computer support, however, other aspects such as power, conflict and control must also be considered....

  1. Group Cooperation without Group Selection: Modest Punishment Can Recruit Much Cooperation.

    Science.gov (United States)

    Krasnow, Max M; Delton, Andrew W; Cosmides, Leda; Tooby, John

    2015-01-01

    Humans everywhere cooperate in groups to achieve benefits not attainable by individuals. Individual effort is often not automatically tied to a proportionate share of group benefits. This decoupling allows for free-riding, a strategy that (absent countermeasures) outcompetes cooperation. Empirically and formally, punishment potentially solves the evolutionary puzzle of group cooperation. Nevertheless, standard analyses appear to show that punishment alone is insufficient, because second-order free riders (those who cooperate but do not punish) can be shown to outcompete punishers. Consequently, many have concluded that other processes, such as cultural or genetic group selection, are required. Here, we present a series of agent-based simulations that show that group cooperation sustained by punishment easily evolves by individual selection when you introduce into standard models more biologically plausible assumptions about the social ecology and psychology of ancestral humans. We relax three unrealistic assumptions of past models. First, past models assume all punishers must punish every act of free riding in their group. We instead allow punishment to be probabilistic, meaning punishers can evolve to only punish some free riders some of the time. This drastically lowers the cost of punishment as group size increases. Second, most models unrealistically do not allow punishment to recruit labor; punishment merely reduces the punished agent's fitness. We instead realistically allow punished free riders to cooperate in the future to avoid punishment. Third, past models usually restrict agents to interact in a single group their entire lives. We instead introduce realistic social ecologies in which agents participate in multiple, partially overlapping groups. Because of this, punitive tendencies are more expressed and therefore more exposed to natural selection. These three moves toward greater model realism reveal that punishment and cooperation easily evolve by

  2. Group Cooperation without Group Selection: Modest Punishment Can Recruit Much Cooperation.

    Directory of Open Access Journals (Sweden)

    Max M Krasnow

    Full Text Available Humans everywhere cooperate in groups to achieve benefits not attainable by individuals. Individual effort is often not automatically tied to a proportionate share of group benefits. This decoupling allows for free-riding, a strategy that (absent countermeasures outcompetes cooperation. Empirically and formally, punishment potentially solves the evolutionary puzzle of group cooperation. Nevertheless, standard analyses appear to show that punishment alone is insufficient, because second-order free riders (those who cooperate but do not punish can be shown to outcompete punishers. Consequently, many have concluded that other processes, such as cultural or genetic group selection, are required. Here, we present a series of agent-based simulations that show that group cooperation sustained by punishment easily evolves by individual selection when you introduce into standard models more biologically plausible assumptions about the social ecology and psychology of ancestral humans. We relax three unrealistic assumptions of past models. First, past models assume all punishers must punish every act of free riding in their group. We instead allow punishment to be probabilistic, meaning punishers can evolve to only punish some free riders some of the time. This drastically lowers the cost of punishment as group size increases. Second, most models unrealistically do not allow punishment to recruit labor; punishment merely reduces the punished agent's fitness. We instead realistically allow punished free riders to cooperate in the future to avoid punishment. Third, past models usually restrict agents to interact in a single group their entire lives. We instead introduce realistic social ecologies in which agents participate in multiple, partially overlapping groups. Because of this, punitive tendencies are more expressed and therefore more exposed to natural selection. These three moves toward greater model realism reveal that punishment and cooperation

  3. Minefield Mapping Using Cooperative Multirobot Systems

    Directory of Open Access Journals (Sweden)

    Alaa Khamis

    2012-01-01

    Full Text Available This paper presents a team-theoretic approach to cooperative multirobot systems. The individual actions of the robots are controlled by the Belief-Desire-Intention model to endow the robots with the know-how needed to execute these actions deliberately. The cooperative behaviors between the heterogeneous robots are governed by the Team-Log theory to endow all the robots in the team with the know-how-to-cooperate and determine the team members’ commitments to each other despite their different types, properties, and goals. The proposed approach is tested for validity with the real life problem of minefield mapping. Different minefield sweeping strategies are studied to control the mobility of the mobile sweepers within the minefield in order to maximize the area coverage and improve picture compilation capability of the multirobot system.

  4. Cooperative strategies European perspectives

    CERN Document Server

    Killing, J Peter

    1997-01-01

    Cooperative Strategies: European Perspectives is one of three geographically targeted volumes in which the contributors present the most current research on topics such as advances in theories of cooperative strategies, the formation of cooperative alliances, the dynamics of partner relationships, and the role of information and knowledge in cooperative alliances. Blending conceptual insights with empirical analyses, the contributors highlight commonalities and differences across national, cultural, and trade zones. The chapters in this volume are anchored in a wide set of theoretical approaches, conceptual frameworks, and models, illustrating how rich the area of cooperative strategies is for scholarly inquiry.

  5. Chemical Agents

    Science.gov (United States)

    ... CR) see Riot Control Agents Digitalis Distilled mustard (HD) see Sulfur mustard E Ethylene glycol F Fentanyls and other opioids H Hydrazine Hydrofluoric acid (hydrogen fluoride) Hydrogen chloride Hydrogen cyanide (AC) Hydrogen ...

  6. Heterogeneous network architectures

    DEFF Research Database (Denmark)

    Christiansen, Henrik Lehrmann

    2006-01-01

    is flexibility. This thesis investigates such heterogeneous network architectures and how to make them flexible. A survey of algorithms for network design is presented, and it is described how using heuristics can increase the speed. A hierarchical, MPLS based network architecture is described......Future networks will be heterogeneous! Due to the sheer size of networks (e.g., the Internet) upgrades cannot be instantaneous and thus heterogeneity appears. This means that instead of trying to find the olution, networks hould be designed as being heterogeneous. One of the key equirements here...... and it is discussed that it is advantageous to heterogeneous networks and illustrated by a number of examples. Modeling and simulation is a well-known way of doing performance evaluation. An approach to event-driven simulation of communication networks is presented and mixed complexity modeling, which can simplify...

  7. Social Stratification and Cooperative Behavior in Spatial Prisoners' Dilemma Games.

    Directory of Open Access Journals (Sweden)

    Peng Lu

    Full Text Available It has been a long-lasting pursuit to promote cooperation, and this study aims to promote cooperation via the combination of social stratification and the spatial prisoners' dilemma game. It is previously assumed that agents share the identical payoff matrix, but the stratification or diversity exists and exerts influences in real societies. Thus, two additional classes, elites and scoundrels, derive from and coexist with the existing class, commons. Three classes have different payoff matrices. We construct a model where agents play the prisoners' dilemma game with neighbors. It indicates that stratification and temptation jointly influence cooperation. Temptation permanently reduces cooperation; elites play a positive role in promoting cooperation while scoundrels undermine it. As the temptation getting larger and larger, elites play a more and more positive and critical role while scoundrels' negative effect becomes weaker and weaker, and it is more obvious when temptation goes beyond its threshold.

  8. Models in cooperative game theory crisp, fuzzy, and multi-choice games

    CERN Document Server

    Branzei, Rodica; Tijs, Stef

    2005-01-01

    This book investigates models in cooperative game theory in which the players have the possibility to cooperate partially. In a crisp game the agents are either fully involved or not involved at all in coperation with some other agents, while in a fuzzy game players are allowed to cooperate with infinite many different participation levels, varying from non-cooperation to full cooperation. A multi-choice game describes the intermediate case in which each player may have a fixed number of activity levels. Different set and one-point solution concepts for these games are presented. The propertie

  9. Heterogeneous cellular networks

    CERN Document Server

    Hu, Rose Qingyang

    2013-01-01

    A timely publication providing coverage of radio resource management, mobility management and standardization in heterogeneous cellular networks The topic of heterogeneous cellular networks has gained momentum in industry and the research community, attracting the attention of standardization bodies such as 3GPP LTE and IEEE 802.16j, whose objectives are looking into increasing the capacity and coverage of the cellular networks. This book focuses on recent progresses,  covering the related topics including scenarios of heterogeneous network deployment, interference management i

  10. Multiagent cooperation and competition with deep reinforcement learning.

    Directory of Open Access Journals (Sweden)

    Ardi Tampuu

    Full Text Available Evolution of cooperation and competition can appear when multiple adaptive agents share a biological, social, or technological niche. In the present work we study how cooperation and competition emerge between autonomous agents that learn by reinforcement while using only their raw visual input as the state representation. In particular, we extend the Deep Q-Learning framework to multiagent environments to investigate the interaction between two learning agents in the well-known video game Pong. By manipulating the classical rewarding scheme of Pong we show how competitive and collaborative behaviors emerge. We also describe the progression from competitive to collaborative behavior when the incentive to cooperate is increased. Finally we show how learning by playing against another adaptive agent, instead of against a hard-wired algorithm, results in more robust strategies. The present work shows that Deep Q-Networks can become a useful tool for studying decentralized learning of multiagent systems coping with high-dimensional environments.

  11. Multiagent cooperation and competition with deep reinforcement learning.

    Science.gov (United States)

    Tampuu, Ardi; Matiisen, Tambet; Kodelja, Dorian; Kuzovkin, Ilya; Korjus, Kristjan; Aru, Juhan; Aru, Jaan; Vicente, Raul

    2017-01-01

    Evolution of cooperation and competition can appear when multiple adaptive agents share a biological, social, or technological niche. In the present work we study how cooperation and competition emerge between autonomous agents that learn by reinforcement while using only their raw visual input as the state representation. In particular, we extend the Deep Q-Learning framework to multiagent environments to investigate the interaction between two learning agents in the well-known video game Pong. By manipulating the classical rewarding scheme of Pong we show how competitive and collaborative behaviors emerge. We also describe the progression from competitive to collaborative behavior when the incentive to cooperate is increased. Finally we show how learning by playing against another adaptive agent, instead of against a hard-wired algorithm, results in more robust strategies. The present work shows that Deep Q-Networks can become a useful tool for studying decentralized learning of multiagent systems coping with high-dimensional environments.

  12. Multiagent cooperation and competition with deep reinforcement learning

    Science.gov (United States)

    Kodelja, Dorian; Kuzovkin, Ilya; Korjus, Kristjan; Aru, Juhan; Aru, Jaan; Vicente, Raul

    2017-01-01

    Evolution of cooperation and competition can appear when multiple adaptive agents share a biological, social, or technological niche. In the present work we study how cooperation and competition emerge between autonomous agents that learn by reinforcement while using only their raw visual input as the state representation. In particular, we extend the Deep Q-Learning framework to multiagent environments to investigate the interaction between two learning agents in the well-known video game Pong. By manipulating the classical rewarding scheme of Pong we show how competitive and collaborative behaviors emerge. We also describe the progression from competitive to collaborative behavior when the incentive to cooperate is increased. Finally we show how learning by playing against another adaptive agent, instead of against a hard-wired algorithm, results in more robust strategies. The present work shows that Deep Q-Networks can become a useful tool for studying decentralized learning of multiagent systems coping with high-dimensional environments. PMID:28380078

  13. Is Cooperative Memory Special? The Role of Costly Errors, Context, and Social Network Size When Remembering Cooperative Actions

    Directory of Open Access Journals (Sweden)

    Tim Winke

    2017-10-01

    require excellent memory. Thus, modeling the evolution of cooperation requires an understanding of both the social environment in which agents interact and the cognitive capabilities of these agents.

  14. Multi-agent and complex systems

    CERN Document Server

    Ren, Fenghui; Fujita, Katsuhide; Zhang, Minjie; Ito, Takayuki

    2017-01-01

    This book provides a description of advanced multi-agent and artificial intelligence technologies for the modeling and simulation of complex systems, as well as an overview of the latest scientific efforts in this field. A complex system features a large number of interacting components, whose aggregate activities are nonlinear and self-organized. A multi-agent system is a group or society of agents which interact with others cooperatively and/or competitively in order to reach their individual or common goals. Multi-agent systems are suitable for modeling and simulation of complex systems, which is difficult to accomplish using traditional computational approaches.

  15. Neurobiological heterogeneity in ADHD

    NARCIS (Netherlands)

    de Zeeuw, P.

    2011-01-01

    Attention-Deficit/Hyperactivity Disorder (ADHD) is a highly heterogeneous disorder clinically. Symptoms take many forms, from subtle but pervasive attention problems or dreaminess up to disruptive and unpredictable behavior. Interestingly, early neuroscientific work on ADHD assumed either a

  16. Heterogeneous Calculation of {epsilon}

    Energy Technology Data Exchange (ETDEWEB)

    Jonsson, Alf

    1961-02-15

    A heterogeneous method of calculating the fast fission factor given by Naudet has been applied to the Carlvik - Pershagen definition of {epsilon}. An exact calculation of the collision probabilities is included in the programme developed for the Ferranti - Mercury computer.

  17. Heterogeneous Calculation of ε

    International Nuclear Information System (INIS)

    Jonsson, Alf

    1961-02-01

    A heterogeneous method of calculating the fast fission factor given by Naudet has been applied to the Carlvik - Pershagen definition of ε. An exact calculation of the collision probabilities is included in the programme developed for the Ferranti - Mercury computer

  18. HETEROGENEOUS INTEGRATION TECHNOLOGY

    Science.gov (United States)

    2017-08-24

    AFRL-RY-WP-TR-2017-0168 HETEROGENEOUS INTEGRATION TECHNOLOGY Dr. Burhan Bayraktaroglu Devices for Sensing Branch Aerospace Components & Subsystems...Final September 1, 2016 – May 1, 2017 4. TITLE AND SUBTITLE HETEROGENEOUS INTEGRATION TECHNOLOGY 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER N/A...provide a structure for this review. The history and the current status of integration technologies in each category are examined and product examples are

  19. Determining the Influence of Heterogeneity in Graduate Institutions on University-Industry Collaboration Policy in Taiwan

    Science.gov (United States)

    Weng, Hung-Jen; Chang, Dian-Fu

    2016-01-01

    In this study, we assumed that organizational heterogeneity is a key factor influencing the effects of university-industry cooperation policy in higher education institutes. Gender difference, faculty position, faculty member nationality, and diversity in academic expertise were considered as the indicators of heterogeneity. One-hundred graduate…

  20. International co-operation

    International Nuclear Information System (INIS)

    Klinda, J.; Lieskovska, Z.

    1998-01-01

    Within the Union Nations (UN) framework, the Slovak Republic participated in following activities on environment protection co-operation: UN European Economic Commission, UN Industrial Development Organization, UN Development Programme, UN Human Habitat Organization, UN Environment Programme, and UN Commission on Sustainable Development. Relevant activities of the Slovak Republic in these co-operations as well as in European Union and OECD activities are reviewed. International conventions and other forms of multilateral co-operation, bilateral co-operation, and international programmes and projects in which the Slovak Republic took participate are presented

  1. Cooperative Station History Forms

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Various forms, photographs and correspondence documenting the history of Cooperative station instrumentation, location changes, inspections, and...

  2. Heterogeneous gas core reactor

    International Nuclear Information System (INIS)

    Han, K.I.

    1977-01-01

    Preliminary investigations of a heterogeneous gas core reactor (HGCR) concept suggest that this potential power reactor offers distinct advantages over other existing or conceptual reactor power plants. One of the most favorable features of the HGCR is the flexibility of the power producing system which allows it to be efficiently designed to conform to a desired optimum condition without major conceptual changes. The arrangement of bundles of moderator/coolant channels in a fissionable gas or mixture of gases makes a truly heterogeneous nuclear reactor core. It is this full heterogeneity for a gas-fueled reactor core which accounts for the novelty of the heterogeneous gas core reactor concept and leads to noted significant advantages over previous gas core systems with respect to neutron and fuel economy, power density, and heat transfer characteristics. The purpose of this work is to provide an insight into the design, operating characteristics, and safety of a heterogeneous gas core reactor system. The studies consist mainly of neutronic, energetic and kinetic analyses of the power producing and conversion systems as a preliminary assessment of the heterogeneous gas core reactor concept and basic design. The results of the conducted research indicate a high potential for the heterogeneous gas core reactor system as an electrical power generating unit (either large or small), with an overall efficiency as high as 40 to 45%. The HGCR system is found to be stable and safe, under the conditions imposed upon the analyses conducted in this work, due to the inherent safety of ann expanding gaseous fuel and the intrinsic feedback effects of the gas and water coolant

  3. Origins of human cooperation and morality.

    Science.gov (United States)

    Tomasello, Michael; Vaish, Amrisha

    2013-01-01

    From an evolutionary perspective, morality is a form of cooperation. Cooperation requires individuals either to suppress their own self-interest or to equate it with that of others. We review recent research on the origins of human morality, both phylogenetic (research with apes) and ontogenetic (research with children). For both time frames we propose a two-step sequence: first a second-personal morality in which individuals are sympathetic or fair to particular others, and second an agent-neutral morality in which individuals follow and enforce group-wide social norms. Human morality arose evolutionarily as a set of skills and motives for cooperating with others, and the ontogeny of these skills and motives unfolds in part naturally and in part as a result of sociocultural contexts and interactions.

  4. Heterogeneous fundamentalists and market maker inventories

    International Nuclear Information System (INIS)

    Carraro, Alessandro; Ricchiuti, Giorgio

    2015-01-01

    In this paper, we develop a heterogeneous agents model of asset price and inventory with a market maker who considers the excess demand of two groups of agents that employ the same trading rule (i.e. fundamentalists) with different beliefs on the fundamental value. The dynamics of our model is driven by a bi-dimensional discrete non-linear map. We show that the market maker has a destabilizing role when she actively manages the inventory. Moreover, inventory share and the distance between agents’ beliefs strongly influence the results: market instability and periodic, or even, chaotic price fluctuations can be generated. Finally, we show through simulations that endogenous fluctuations of the fractions of agents may trigger instability for a larger set of parameters.

  5. Predisposed to cooperate

    Directory of Open Access Journals (Sweden)

    Cathryn Costello

    2013-09-01

    Full Text Available Recent research in Toronto and Geneva indicates that asylum seekers and refugees are predisposed to be cooperative with the refugee status determination system and other immigration procedures, and that the design of alternatives to detention can create, foster and support this cooperative predisposition – or can undermine or even demolish it.

  6. Proto-cooperation

    DEFF Research Database (Denmark)

    Herbert-Read, James E; Romanczuk, Pawel; Krause, Stefan

    2016-01-01

    beneficial if the cost of attacking is high, and only then when waiting times are short. Our findings provide evidence that cooperative benefits can be realized through the facilitative effects of individuals' hunting actions without spatial coordination of attacks. Such 'proto-cooperation' may be the pre...

  7. Scandinavian Cooperative Advantage

    DEFF Research Database (Denmark)

    Strand, Robert; Freeman, R. Edward

    2015-01-01

    . We conclude by endorsing the expression “Scandinavian cooperative advantage” in an effort to draw attention to the Scandinavian context and encourage the field of strategic management to shift its focus from achieving a competitive advantage toward achieving a cooperative advantage....

  8. Helping Children Cooperate

    Science.gov (United States)

    Pica, Rae

    2011-01-01

    There are occasions in life when the competitive process is appropriate. But when people consider the relationships in their lives--with friends, family members, coworkers, and the larger community--they realize the value of cooperation. When adults give children the chance to cooperate, to work together toward a solution or a common goal like…

  9. Optimal government policies in models with heterogeneous agents

    Czech Academy of Sciences Publication Activity Database

    Boháček, Radim; Kejak, Michal

    -, č. 272 (2005), s. 1-55 ISSN 1211-3298 Institutional research plan: CEZ:AV0Z70850503 Keywords : optimal macroeconomic policy * optimal taxation * distribution of wealth and income Subject RIV: AH - Economics http://www.cerge-ei.cz/pdf/wp/Wp272.pdf

  10. Heterogeneous agent model and numerical analysis of learning

    Czech Academy of Sciences Publication Activity Database

    Vošvrda, Miloslav; Vácha, Lukáš

    2002-01-01

    Roč. 9, č. 17 (2002), s. 15-22 ISSN 1212-074X R&D Projects: GA ČR GA402/01/0034; GA ČR GA402/01/0539; GA AV ČR IAA7075202 Institutional research plan: CEZ:AV0Z1075907 Keywords : efficient markets hypothesis * technical trading rules * numerical analysis of learning Subject RIV: AH - Economics

  11. The evolution of cooperation by the Hankshaw effect.

    Science.gov (United States)

    Hammarlund, Sarah P; Connelly, Brian D; Dickinson, Katherine J; Kerr, Benjamin

    2016-06-01

    The evolution of cooperation-costly behavior that benefits others-faces one clear obstacle. Namely, cooperators are always at a competitive disadvantage relative to defectors, individuals that reap the benefits, but evade the cost of cooperation. One solution to this problem involves genetic hitchhiking, where the allele encoding cooperation becomes linked to a beneficial mutation, allowing cooperation to rise in abundance. Here, we explore hitchhiking in the context of adaptation to a stressful environment by cooperators and defectors with spatially limited dispersal. Under such conditions, clustered cooperators reach higher local densities, thereby experiencing more mutational opportunities than defectors. Thus, the allele encoding cooperation has a greater probability of hitchhiking with alleles conferring stress adaptation. We label this probabilistic enhancement the "Hankshaw effect" after the character Sissy Hankshaw, whose anomalously large thumbs made her a singularly effective hitchhiker. Using an agent-based model, we reveal a broad set of conditions that allow the evolution of cooperation through this effect. Additionally, we show that spite, a costly behavior that harms others, can evolve by the Hankshaw effect. While in an unchanging environment these costly social behaviors have transient success, in a dynamic environment, cooperation and spite can persist indefinitely. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  12. Social aggregation as a cooperative game

    Science.gov (United States)

    Vilone, Daniele; Guazzini, Andrea

    2011-07-01

    A new approach for the description of phenomena of social aggregation is suggested. On the basis of psychological concepts (as for instance social norms and cultural coordinates), we deduce a general mechanism for social aggregation in which different clusters of individuals can merge according to cooperation among the agents. In their turn, the agents can cooperate or defect according to the clusters' distribution inside the system. The fitness of an individual increases with the size of its cluster, but decreases with the work the individual had to do in order to join it. In order to test the reliability of such a new approach, we introduce a couple of simple toy models with the features illustrated above. We see, from this preliminary study, how cooperation is the most convenient strategy only in the presence of very large clusters, while on the other hand it is not necessary to have one hundred percent of cooperators for reaching a totally ordered configuration with only one megacluster filling the whole system.

  13. Efficiency in Microfinance Cooperatives

    Directory of Open Access Journals (Sweden)

    HARTARSKA, Valentina

    2012-12-01

    Full Text Available In recognition of cooperatives’ contribution to the socio-economic well-being of their participants, the United Nations has declared 2012 as the International Year of Cooperatives. Microfinance cooperatives make a large part of the microfinance industry. We study efficiency of microfinance cooperatives and provide estimates of the optimal size of such organizations. We employ the classical efficiency analysis consisting of estimating a system of equations and identify the optimal size of microfinance cooperatives in terms of their number of clients (outreach efficiency, as well as dollar value of lending and deposits (sustainability. We find that microfinance cooperatives have increasing returns to scale which means that the vast majority can lower cost if they become larger. We calculate that the optimal size is around $100 million in lending and half of that in deposits. We find less robust estimates in terms of reaching many clients with a range from 40,000 to 180,000 borrowers.

  14. [Biological agents].

    Science.gov (United States)

    Amano, Koichi

    2009-03-01

    There are two types of biological agents for the treatment of rheumatoid arthritis (RA); monoclonal antibodies and recombinant proteins. Among the latter, etanercept, a recombinant fusion protein of soluble TNF receptor and IgG was approved in 2005 in Japan. The post-marketing surveillance of 13,894 RA patients revealed the efficacy and safety profiles of etanercept in the Japanese population, as well as overseas studies. Abatacept, a recombinant fusion protein of CTLA4 and IgG, is another biological agent for RA. Two clinical trials disclosed the efficacy of abatacept for difficult-to-treat patients: the AIM for MTX-resistant cases and the ATTAIN for patients who are resistant to anti-TNF. The ATTEST trial suggested abatacept might have more acceptable safety profile than infliximab. These biologics are also promising for the treatment of RA for not only relieving clinical symptoms and signs but retarding structural damage.

  15. The Effect of Cooperative Teaching on the Development of Reading Skills among Students with Reading Disorders

    Science.gov (United States)

    Ghanaat Pisheh, Etrat Alzahra; Sadeghpour, Narges; Nejatyjahromy, Yaser; Mir Nasab, Mir Mahmoud

    2017-01-01

    Cooperative teaching is the result of efforts made by two educators for teaching a heterogeneous group of students, especially one including those with specific needs, due to reading disorders for instance. The present study serves as an experimental investigation focusing on the effect of cooperative teaching on the development of reading skills…

  16. Green heterogeneous wireless networks

    CERN Document Server

    Ismail, Muhammad; Nee, Hans-Peter; Qaraqe, Khalid A; Serpedin, Erchin

    2016-01-01

    This book focuses on the emerging research topic "green (energy efficient) wireless networks" which has drawn huge attention recently from both academia and industry. This topic is highly motivated due to important environmental, financial, and quality-of-experience (QoE) considerations. Specifically, the high energy consumption of the wireless networks manifests in approximately 2% of all CO2 emissions worldwide. This book presents the authors’ visions and solutions for deployment of energy efficient (green) heterogeneous wireless communication networks. The book consists of three major parts. The first part provides an introduction to the "green networks" concept, the second part targets the green multi-homing resource allocation problem, and the third chapter presents a novel deployment of device-to-device (D2D) communications and its successful integration in Heterogeneous Networks (HetNets). The book is novel in that it specifically targets green networking in a heterogeneous wireless medium, which re...

  17. Isotopes in heterogeneous catalysis

    CERN Document Server

    Hargreaves, Justin SJ

    2006-01-01

    The purpose of this book is to review the current, state-of-the-art application of isotopic methods to the field of heterogeneous catalysis. Isotopic studies are arguably the ultimate technique in in situ methods for heterogeneous catalysis. In this review volume, chapters have been contributed by experts in the field and the coverage includes both the application of specific isotopes - Deuterium, Tritium, Carbon-14, Sulfur-35 and Oxygen-18 - as well as isotopic techniques - determination of surface mobility, steady state transient isotope kinetic analysis, and positron emission profiling.

  18. Cancer heterogeneity and imaging.

    Science.gov (United States)

    O'Connor, James P B

    2017-04-01

    There is interest in identifying and quantifying tumor heterogeneity at the genomic, tissue pathology and clinical imaging scales, as this may help better understand tumor biology and may yield useful biomarkers for guiding therapy-based decision making. This review focuses on the role and value of using x-ray, CT, MRI and PET based imaging methods that identify, measure and map tumor heterogeneity. In particular we highlight the potential value of these techniques and the key challenges required to validate and qualify these biomarkers for clinical use. Copyright © 2016. Published by Elsevier Ltd.

  19. Game theory in communication networks cooperative resolution of interactive networking scenarios

    CERN Document Server

    Antoniou, Josephina

    2012-01-01

    A mathematical tool for scientists and researchers who work with computer and communication networks, Game Theory in Communication Networks: Cooperative Resolution of Interactive Networking Scenarios addresses the question of how to promote cooperative behavior in interactive situations between heterogeneous entities in communication networking scenarios. It explores network design and management from a theoretical perspective, using game theory and graph theory to analyze strategic situations and demonstrate profitable behaviors of the cooperative entities. The book promotes the use of Game T

  20. BRAIN Journal - The Impact of Cooperative Learning on Female Medical Students' Happiness and Social Support

    OpenAIRE

    Ali Taghinezhad; Rahim Pendar; Samira Rahimi; Maryam Jamalzadeh; Mahboobeh Azadikhah

    2017-01-01

    ABSTRACT Cooperative learning has appeared as a new approach to teaching. This approach is utilized for small heterogeneous groups of students who cooperate to achieve a common goal. This study aimed at investigating the impact of cooperative learning on female medical students’ happiness and social support. To this end, 72 female students of medicine at Shiraz Medical School were selected using cluster sampling and divided into experimental and control groups. The students were administe...

  1. What drives cooperative breeding?

    Directory of Open Access Journals (Sweden)

    Walter D Koenig

    2017-06-01

    Full Text Available Cooperative breeding, in which more than a pair of conspecifics cooperate to raise young at a single nest or brood, is widespread among vertebrates but highly variable in its geographic distribution. Particularly vexing has been identifying the ecological correlates of this phenomenon, which has been suggested to be favored in populations inhabiting both relatively stable, productive environments and in populations living under highly variable and unpredictable conditions. Griesser et al. provide a novel approach to this problem, performing a phylogenetic analysis indicating that family living is an intermediate step between nonsocial and cooperative breeding birds. They then examine the ecological and climatic conditions associated with these different social systems, concluding that cooperative breeding emerges when family living is favored in highly productive environments, followed secondarily by selection for cooperative breeding when environmental conditions deteriorate and within-year variability increases. Combined with recent work addressing the fitness consequences of cooperative breeding, Griesser et al.'s contribution stands to move the field forward by demonstrating that the evolution of complex adaptations such as cooperative breeding may only be understood when each of the steps leading to it are identified and carefully integrated.

  2. Cognitive Load and Cooperation

    DEFF Research Database (Denmark)

    Døssing, Felix Sebastian; Piovesan, Marco; Wengström, Erik Roland

    2017-01-01

    We study the effect of intuitive and reflective processes on cooperation using cognitive load. Compared with time constraint, which has been used in the previous literature, cognitive load is a more direct way to block reflective processes, and thus a more suitable way to study the link between...... intuition and cooperation. Using a repeated public goods game, we study the effect of different levels of cognitive load on contributions. We show that a higher cognitive load increases the initial level of cooperation. In particular, subjects are significantly less likely to fully free ride under high...... cognitive load....

  3. Nordic Energy Policy Cooperation

    DEFF Research Database (Denmark)

    Jørgensen, Birte Holst

    2016-01-01

    Brundtland Commission Report, and climate change became a common concern. Energy technology cooperation was an integral part of Nordic energy policy cooperation from the very beginning. The Nordic Energy Research Programme was established with funding from each of the Nordic countries, and was earmarked...... by a committee of senior officials and a secretariat. This was characterised by an incremental development of the cooperation based on consensus, mutual understanding and trust facilitated through exchange of experiences, work groups, seminars, educational activities and mobility schemes for energy policy...

  4. Cooperative Mobile Web Browsing

    DEFF Research Database (Denmark)

    Perrucci, GP; Fitzek, FHP; Zhang, Qi

    2009-01-01

    This paper advocates a novel approach for mobile web browsing based on cooperation among wireless devices within close proximity operating in a cellular environment. In the actual state of the art, mobile phones can access the web using different cellular technologies. However, the supported data......-range links can then be used for cooperative mobile web browsing. By implementing the cooperative web browsing on commercial mobile phones, it will be shown that better performance is achieved in terms of increased data rate and therefore reduced access times, resulting in a significantly enhanced web...

  5. Trading Agents

    CERN Document Server

    Wellman, Michael

    2011-01-01

    Automated trading in electronic markets is one of the most common and consequential applications of autonomous software agents. Design of effective trading strategies requires thorough understanding of how market mechanisms operate, and appreciation of strategic issues that commonly manifest in trading scenarios. Drawing on research in auction theory and artificial intelligence, this book presents core principles of strategic reasoning that apply to market situations. The author illustrates trading strategy choices through examples of concrete market environments, such as eBay, as well as abst

  6. Swarm intelligence inspired shills and the evolution of cooperation

    OpenAIRE

    Duan, Haibin; Sun, Changhao

    2014-01-01

    Many hostile scenarios exist in real-life situations, where cooperation is disfavored and the collective behavior needs intervention for system efficiency improvement. Towards this end, the framework of soft control provides a powerful tool by introducing controllable agents called shills, who are allowed to follow well-designed updating rules for varying missions. Inspired by swarm intelligence emerging from flocks of birds, we explore here the dependence of the evolution of cooperation on s...

  7. Cooperative SIS epidemics can lead to abrupt outbreaks

    Science.gov (United States)

    Ghanbarnejad, Fakhteh; Chen, Li; Cai, Weiran; Grassberger, Peter

    2015-03-01

    In this paper, we study spreading of two cooperative SIS epidemics in mean field approximations and also within an agent based framework. Therefore we investigate dynamics on different topologies like Erdos-Renyi networks and regular lattices. We show that cooperativity of two diseases can lead to strongly first order outbreaks, while the dynamics still might present some scaling laws typical for second order phase transitions. We argue how topological network features might be related to this interesting hybrid behaviors.

  8. Heterogeneity and Networks

    OpenAIRE

    Goyal, S.

    2018-01-01

    This chapter shows that networks can have large and differentiated effects on behavior and then argues that social and economic pressures facilitate the formation of heterogenous networks. Thus networks can play an important role in understanding the wide diversity in human behaviour and in economic outcomes.

  9. Heterogeneous Computing in Economics

    DEFF Research Database (Denmark)

    Dziubinski, M.P.; Grassi, S.

    2014-01-01

    This paper shows the potential of heterogeneous computing in solving dynamic equilibrium models in economics. We illustrate the power and simplicity of C++ Accelerated Massive Parallelism (C++ AMP) recently introduced by Microsoft. Starting from the same exercise as Aldrich et al. (J Econ Dyn...

  10. Heterogeneity of Dutch rainfall

    NARCIS (Netherlands)

    Witter, J.V.

    1984-01-01

    Rainfall data for the Netherlands have been used in this study to investigate aspects of heterogeneity of rainfall, in particular local differences in rainfall levels, time trends in rainfall, and local differences in rainfall trend. The possible effect of urbanization and industrialization on the

  11. in Heterogeneous Media

    Directory of Open Access Journals (Sweden)

    Saeed Balouchi

    2013-01-01

    Full Text Available Fractured reservoirs contain about 85 and 90 percent of oil and gas resources respectively in Iran. A comprehensive study and investigation of fractures as the main factor affecting fluid flow or perhaps barrier seems necessary for reservoir development studies. High degrees of heterogeneity and sparseness of data have incapacitated conventional deterministic methods in fracture network modeling. Recently, simulated annealing (SA has been applied to generate stochastic realizations of spatially correlated fracture networks by assuming that the elastic energy of fractures follows Boltzmann distribution. Although SA honors local variability, the objective function of geometrical fracture modeling is defined for homogeneous conditions. In this study, after the introduction of SA and the derivation of the energy function, a novel technique is presented to adjust the model with highly heterogeneous data for a fractured field from the southwest of Iran. To this end, the regular object-based model is combined with a grid-based technique to cover the heterogeneity of reservoir properties. The original SA algorithm is also modified by being constrained in different directions and weighting the energy function to make it appropriate for heterogeneous conditions. The simulation results of the presented approach are in good agreement with the observed field data.

  12. Heterogeneous chromium catalysts

    NARCIS (Netherlands)

    2005-01-01

    The present invention relates to a heterogeneous chromium catalyst system for the polymerisation of ethylene and/or alpha olefins prepared by the steps of: (a) providing a silica-containing support, (b) treating the silica-containing support with a chromium compound to form a chromium-based

  13. Why does heterogeneity matter?

    Science.gov (United States)

    K.B. Pierce

    2007-01-01

    This is a review of the book "Ecosystem function in heterogeneous landscapes" published in 2005. The authors are G. Lovett, C. Jones, M.G. Turner, and K.C. Weathers. It was published by Springer, New York. The book is a synthesis of the 10th Gary conference held at the Institute of Ecosystem Studies in Millbrook, New York, in 2003.

  14. Social identity and cooperation in cultural evolution.

    Science.gov (United States)

    Smaldino, Paul E

    2017-12-06

    I discuss the function of social identity signaling in facilitating cooperative group formation, and how the nature of that function changes with the structure of social organization. I propose that signals of social identity facilitate assortment for successful coordination in large-scale societies, and that the multidimensional, context-dependent nature of social identity is crucial for successful coordination when individuals have to cooperate in different contexts. Furthermore, the structure of social identity is tied to the structure of society, so that as societies grow larger and more interconnected, the landscape of social identities grows more heterogeneous. This discussion bears directly on the need to articulate the dynamics of emergent, ephemeral groups as a major factor in human cultural evolution. Copyright © 2017 The Author. Published by Elsevier B.V. All rights reserved.

  15. Semiotics, Multi-Agent Systems and Organizations

    NARCIS (Netherlands)

    Gazendam, H.W.M.; Jorna, René J.

    1998-01-01

    Multi-agent systems are promising as models of organization because they are based on the idea that most work in human organizations is done based on intelligence, communication, cooperation, and massive parallel processing. They offer an alternative for system theories of organization, which are

  16. Heterogeneous Materials I and Heterogeneous Materials II

    International Nuclear Information System (INIS)

    Knowles, K M

    2004-01-01

    In these two volumes the author provides a comprehensive survey of the various mathematically-based models used in the research literature to predict the mechanical, thermal and electrical properties of hetereogeneous materials, i.e., materials containing two or more phases such as fibre-reinforced polymers, cast iron and porous ceramic kiln furniture. Volume I covers linear properties such as linear dielectric constant, effective electrical conductivity and elastic moduli, while Volume II covers nonlinear properties, fracture and atomistic and multiscale modelling. Where appropriate, particular attention is paid to the use of fractal geometry and percolation theory in describing the structure and properties of these materials. The books are advanced level texts reflecting the research interests of the author which will be of significant interest to research scientists working at the forefront of the areas covered by the books. Others working more generally in the field of materials science interested in comparing predictions of properties with experimental results may well find the mathematical level quite daunting initially, as it is apparent that the author assumes a level of mathematics consistent with that taught in final year undergraduate and graduate theoretical physics courses. However, for such readers it is well worth persevering because of the in-depth coverage to which the various models are subjected, and also because of the extensive reference lists at the back of both volumes which direct readers to the various source references in the scientific literature. Thus, for the wider materials science scientific community the two volumes will be a valuable library resource. While I would have liked to see more comparison with experimental data on both ideal and 'real' heterogeneous materials than is provided by the author and a discussion of how to model strong nonlinear current--voltage behaviour in systems such as zinc oxide varistors, my overall

  17. Security Framework for Agent-Based Cloud Computing

    Directory of Open Access Journals (Sweden)

    K Venkateshwaran

    2015-06-01

    Full Text Available Agent can play a key role in bringing suitable cloud services to the customer based on their requirements. In agent based cloud computing, agent does negotiation, coordination, cooperation and collaboration on behalf of the customer to make the decisions in efficient manner. However the agent based cloud computing have some security issues like (a. addition of malicious agent in the cloud environment which could demolish the process by attacking other agents, (b. denial of service by creating flooding attacks on other involved agents. (c. Some of the exceptions in the agent interaction protocol such as Not-Understood and Cancel_Meta protocol can be misused and may lead to terminating the connection of all the other agents participating in the negotiating services. Also, this paper proposes algorithms to solve these issues to ensure that there will be no intervention of any malicious activities during the agent interaction.

  18. Relay tracking control for second-order multi-agent systems with damaged agents.

    Science.gov (United States)

    Dong, Lijing; Li, Jing; Liu, Qin

    2017-11-01

    This paper investigates a situation where smart agents capable of sensory and mobility are deployed to monitor a designated area. A preset number of agents start tracking when a target intrudes this area. Some of the tracking agents are possible to be out of order over the tracking course. Thus, we propose a cooperative relay tracking strategy to ensure the successful tracking with existence of damaged agents. Relay means that, when a tracking agent quits tracking due to malfunction, one of the near deployed agents replaces it to continue the tracking task. This results in jump of tracking errors and dynamic switching of topology of the multi-agent system. Switched system technique is employed to solve this specific problem. Finally, the effectiveness of proposed tracking strategy and validity of the theoretical results are verified by conducting a numerical simulation. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  19. Towards Cooperative Predictive Data Mining in Competitive Environments

    Science.gov (United States)

    Lisý, Viliam; Jakob, Michal; Benda, Petr; Urban, Štěpán; Pěchouček, Michal

    We study the problem of predictive data mining in a competitive multi-agent setting, in which each agent is assumed to have some partial knowledge required for correctly classifying a set of unlabelled examples. The agents are self-interested and therefore need to reason about the trade-offs between increasing their classification accuracy by collaborating with other agents and disclosing their private classification knowledge to other agents through such collaboration. We analyze the problem and propose a set of components which can enable cooperation in this otherwise competitive task. These components include measures for quantifying private knowledge disclosure, data-mining models suitable for multi-agent predictive data mining, and a set of strategies by which agents can improve their classification accuracy through collaboration. The overall framework and its individual components are validated on a synthetic experimental domain.

  20. A remote integrated testbed for cooperating objects

    CERN Document Server

    Dios, Jose Ramiro Martinez-de; Bernabe, Alberto de San; Ollero, Anibal

    2013-01-01

    Testbeds are gaining increasing relevance in research domains and also in industrial applications. However, very few books devoted to testbeds have been published. To the best of my knowledge no book on this topic has been published. This book is particularly interesting for the growing community of testbed developers. I believe the book is also very interesting for researchers in robot-WSN cooperation.This book provides detailed description of a system that can be considered the first testbed that allows full peer-to-peer interoperability between heterogeneous robots and ubiquitous systems su

  1. Mutual cooperation with Brazil

    International Nuclear Information System (INIS)

    Orstein, Roberto M.

    1998-01-01

    The history of the nuclear cooperation between Brazil and Argentina is outlined in the framework of the changing political circumstances. Reference is made to the agreements between both countries and to its implementation

  2. Cooperative Hurricane Network Obs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Observations from the Cooperative Hurricane Reporting Network (CHURN), a special network of stations that provided observations when tropical cyclones approached the...

  3. From cooperation to globalization

    Directory of Open Access Journals (Sweden)

    Gabriela UNGUREANU

    2010-09-01

    Full Text Available Globalization is seen as a consequence of cross-border business. This complex and irreversible process can be seen as an extension of capitalist relations of production or increased interdependence in the economic system. Globalization has given rise to more and more fields of activity worldwide. To meet the challenges of business globalization, many companies form strategic alliances, cooperate or merge with other companies. Cooperation is seen by many companies as an alternative path to success. In recent years joint international associations, licensing, co-production agreements, joint research programs, exploration of consortia and other cooperative relationships between two or more corporations with potential have increased. We notice a cooperation tendency among small-sized companies, especially among those from the developing countries.

  4. Globalization and economic cooperation

    Directory of Open Access Journals (Sweden)

    Javier Divar

    2006-12-01

    Full Text Available Economic globalization is nothing, really, that the universality of capitalism. Not globalized culture, and economic participation, and human rights, ... has only globalized market. We must react by substituting those materialistic values with cooperative economy.

  5. Cooperative processing data bases

    Science.gov (United States)

    Hasta, Juzar

    1991-01-01

    Cooperative processing for the 1990's using client-server technology is addressed. The main theme is concepts of downsizing from mainframes and minicomputers to workstations on a local area network (LAN). This document is presented in view graph form.

  6. Cooperative Transport Planning

    NARCIS (Netherlands)

    Zutt, J.; De Weerdt, M.M.

    2000-01-01

    To test and compare different forms of cooperative planning algorithms developed in the CABS project we use a generic simulator called MARS. Examples in the transportation sector are implemented in this simulator.

  7. On Cooper's Nonparametric Test.

    Science.gov (United States)

    Schmeidler, James

    1978-01-01

    The basic assumption of Cooper's nonparametric test for trend (EJ 125 069) is questioned. It is contended that the proper assumption alters the distribution of the statistic and reduces its usefulness. (JKS)

  8. Regional National Cooperative Observer

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA publication dedicated to issues, news and recognition of observers in the National Weather Service Cooperative Observer program. Issues published regionally...

  9. Cooperative Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly logs include a daily account of temperature extremes and precipitation, along with snow data at some locations. U.S. Cooperative Observer Program (COOP)...

  10. Nuclear cooperation agreements

    International Nuclear Information System (INIS)

    Nuclear cooperation agreements are reviewed in tabular form, especially agreements with developing countries. The reporting countries are the USA, the Federal Republic of Germany, Canada, Australia, Japan, and France. A separate EURATOM list is annexed

  11. Introducing ALAS: A Novel Agent-Oriented Programming Language

    Science.gov (United States)

    Mitrović, Dejan; Ivanović, Mirjana; Vidaković, Milan

    2011-09-01

    Agent-oriented programming languages represent a family of programming languages that provide developers with high-level abstractions and constructs necessary for implementing and using agent-related concepts. In this paper a novel agent-oriented programming language for rapid and efficient development of reactive agents, named ALAS, is presented. The simple, but powerful set of language constructs is designed to support the execution of agents in heterogenous environments, and to enable easy employment of advanced agent features, such as mobility and web service integration.

  12. Coevolution of Artificial Agents Using Evolutionary Computation in Bargaining Game

    Directory of Open Access Journals (Sweden)

    Sangwook Lee

    2015-01-01

    Full Text Available Analysis of bargaining game using evolutionary computation is essential issue in the field of game theory. This paper investigates the interaction and coevolutionary process among heterogeneous artificial agents using evolutionary computation (EC in the bargaining game. In particular, the game performance with regard to payoff through the interaction and coevolution of agents is studied. We present three kinds of EC based agents (EC-agent participating in the bargaining game: genetic algorithm (GA, particle swarm optimization (PSO, and differential evolution (DE. The agents’ performance with regard to changing condition is compared. From the simulation results it is found that the PSO-agent is superior to the other agents.

  13. Attraction and cooperative behavior

    OpenAIRE

    Donja Darai; Silvia Grätz

    2012-01-01

    Being good-looking seems to generate substantial benefits in many social interactions, making the "beauty premium" a not to be underrated economic factor. This paper investigates how physical attractiveness enables people to generate these benefits in the case of cooperation, using field data from a modified one-shot prisoner's dilemma played in a high-stakes television game show. While attractive contestants are not more or less cooperative than less attractive ones, facial attractiveness pr...

  14. Purchasing cooperatives for small employers: performance and prospects.

    Science.gov (United States)

    Wicks, E K; Hall, M A

    2000-01-01

    Health insurance purchasing cooperatives were established in the early to mid-1990s for the purpose of making health insurance more affordable and accessible for small employers. Extensive interviews at six cooperatives reveal that while some cooperatives enrolled large numbers of small employers, most have won only small market shares and a number have struggled for survival, not always successfully. They have allowed small employers to offer individual employees choice of health plans, but none has been able to sustain lower prices than are available in the conventional market. Among the important impediments to their success are limited support from health plans and conflicts over the role of insurance agents.

  15. Research on Heterogeneous Data Exchange based on XML

    Science.gov (United States)

    Li, Huanqin; Liu, Jinfeng

    Integration of multiple data sources is becoming increasingly important for enterprises that cooperate closely with their partners for e-commerce. OLAP enables analysts and decision makers fast access to various materialized views from data warehouses. However, many corporations have internal business applications deployed on different platforms. This paper introduces a model for heterogeneous data exchange based on XML. The system can exchange and share the data among the different sources. The method used to realize the heterogeneous data exchange is given in this paper.

  16. Radioprotective Agents

    Directory of Open Access Journals (Sweden)

    Ilker Kelle

    2008-01-01

    Full Text Available Since1949, a great deal of research has been carried out on the radioprotective activity of various chemical substances. Thiol compounds, compounds which contain –SH radical, different classes of pharmacological agents and other compounds such as vitamine C and WR-2721 have been shown to reduce mortality when administered prior to exposure to a lethal dose of radiation. Recently, honey bee venom as well as that of its components melittin and histamine have shown to be valuable in reduction of radiation-induced damage and also provide prophylactic alternative treatment for serious side effects related with radiotherapy. It has been suggested that the radioprotective activity of bee venom components is related with the stimulation of the hematopoetic system.

  17. An evolutionary model of cooperation, fairness and altruistic punishment in public good games.

    Science.gov (United States)

    Hetzer, Moritz; Sornette, Didier

    2013-01-01

    We identify and explain the mechanisms that account for the emergence of fairness preferences and altruistic punishment in voluntary contribution mechanisms by combining an evolutionary perspective together with an expected utility model. We aim at filling a gap between the literature on the theory of evolution applied to cooperation and punishment, and the empirical findings from experimental economics. The approach is motivated by previous findings on other-regarding behavior, the co-evolution of culture, genes and social norms, as well as bounded rationality. Our first result reveals the emergence of two distinct evolutionary regimes that force agents to converge either to a defection state or to a state of coordination, depending on the predominant set of self- or other-regarding preferences. Our second result indicates that subjects in laboratory experiments of public goods games with punishment coordinate and punish defectors as a result of an aversion against disadvantageous inequitable outcomes. Our third finding identifies disadvantageous inequity aversion as evolutionary dominant and stable in a heterogeneous population of agents endowed initially only with purely self-regarding preferences. We validate our model using previously obtained results from three independently conducted experiments of public goods games with punishment.

  18. An evolutionary model of cooperation, fairness and altruistic punishment in public good games.

    Directory of Open Access Journals (Sweden)

    Moritz Hetzer

    Full Text Available We identify and explain the mechanisms that account for the emergence of fairness preferences and altruistic punishment in voluntary contribution mechanisms by combining an evolutionary perspective together with an expected utility model. We aim at filling a gap between the literature on the theory of evolution applied to cooperation and punishment, and the empirical findings from experimental economics. The approach is motivated by previous findings on other-regarding behavior, the co-evolution of culture, genes and social norms, as well as bounded rationality. Our first result reveals the emergence of two distinct evolutionary regimes that force agents to converge either to a defection state or to a state of coordination, depending on the predominant set of self- or other-regarding preferences. Our second result indicates that subjects in laboratory experiments of public goods games with punishment coordinate and punish defectors as a result of an aversion against disadvantageous inequitable outcomes. Our third finding identifies disadvantageous inequity aversion as evolutionary dominant and stable in a heterogeneous population of agents endowed initially only with purely self-regarding preferences. We validate our model using previously obtained results from three independently conducted experiments of public goods games with punishment.

  19. Information and Heterogeneous Beliefs

    DEFF Research Database (Denmark)

    Christensen, Peter Ove; Qin, Zhenjiang

    2014-01-01

    In an incomplete market with heterogeneous prior beliefs, we show public information can have a substantial impact on the ex ante cost of capital, trading volume, and investor welfare. The Pareto effcient public information system is the system enjoying the maximum ex ante cost of capital...... and the maximum expected abnormal trading volume. Imperfect public information increases the gains-to-trade based on heterogeneously updated posterior beliefs. In an exchange economy, this leads to higher growth in the investors' certainty equivalents and, thus, a higher equilibrium interest rate, whereas the ex...... ante risk premium is unaffected by the informativeness of the public information system. Similar results are obtained in a production economy, but the impact on the ex ante cost of capital is dampened compared to the exchange economy due to welfare improving reductions in real investments to smooth...

  20. We can work it out: An enactive look at cooperation

    Directory of Open Access Journals (Sweden)

    Valentina eFantasia

    2014-08-01

    Full Text Available The past years have seen an increasing debate on cooperation and its unique human character. Philosophers and psychologists have proposed that cooperative activities are characterized by shared goals to which participants are committed through the ability to understand each other’s intentions. Despite its popularity, some serious issues arise with this approach to cooperation. First, one may challenge the assumption that high-level mental processes are necessary for engaging in acting cooperatively. If they are, then how do agents that do not possess such ability (preverbal children, or children with autism who are often claimed to be mind-blind engage in cooperative exchanges, as the evidence suggests? Secondly, to define cooperation as the result of two de-contextualized minds reading each other’s intentions may fail to fully acknowledge the complexity of situated, interactional dynamics and the interplay of variables such as the participants’ relational and personal history and experience. In this paper we challenge such accounts of cooperation, calling for an embodied approach that sees cooperation not only as an individual attitude towards the other, but also as a property of interaction processes. Taking an enactive perspective, we argue that cooperation is an intrinsic part of any interaction, and that there can be cooperative interaction before complex communicative abilities are achieved. The issue then is not whether one is able or not to read the other’s intentions, but what it takes to participate in joint action. From this basic account, it should be possible to build up more complex forms of cooperation as needed. Addressing the study of cooperation in these terms may enhance our understanding of human social development, and foster our knowledge of different ways of engaging with others, as in the case of autism.

  1. Impact of Social Punishment on Cooperative Behavior in Complex Networks

    Science.gov (United States)

    Wang, Zhen; Xia, Cheng-Yi; Meloni, Sandro; Zhou, Chang-Song; Moreno, Yamir

    2013-10-01

    Social punishment is a mechanism by which cooperative individuals spend part of their resources to penalize defectors. In this paper, we study the evolution of cooperation in 2-person evolutionary games on networks when a mechanism for social punishment is introduced. Specifically, we introduce a new kind of role, punisher, which is aimed at reducing the earnings of defectors by applying to them a social fee. Results from numerical simulations show that different equilibria allowing the three strategies to coexist are possible as well as that social punishment further enhance the robustness of cooperation. Our results are confirmed for different network topologies and two evolutionary games. In addition, we analyze the microscopic mechanisms that give rise to the observed macroscopic behaviors in both homogeneous and heterogeneous networks. Our conclusions might provide additional insights for understanding the roots of cooperation in social systems.

  2. Micromechanics of heterogeneous materials

    CERN Document Server

    Buryachenko, Valeriy

    2007-01-01

    Here is an accurate and timely account of micromechanics, which spans materials science, mechanical engineering, applied mathematics, technical physics, geophysics, and biology. The book features rigorous and unified theoretical methods of applied mathematics and statistical physics in the material science of microheterogeneous media. Uniquely, it offers a useful demonstration of the systematic and fundamental research of the microstructure of the wide class of heterogeneous materials of natural and synthetic nature.

  3. Percolation in Heterogeneous Media

    International Nuclear Information System (INIS)

    Vocka, Radim

    1999-01-01

    This work is a theoretical reflection on the problematic of the modeling of heterogeneous media, that is on the way of their simple representation conserving their characteristic features. Two particular problems are addressed in this thesis. Firstly, we study the transport in porous media, that is in a heterogeneous media which structure is quenched. A pore space is represented in a simple way - a pore is symbolized as a tube of a given length and a given diameter. The fact that the correlations in the distribution of pore sizes are taken into account by a construction of a hierarchical network makes possible the modeling of porous media with a porosity distributed over several length scales. The transport in the hierarchical network shows qualitatively different phenomena from those observed in simpler models. A comparison of numerical results with experimental data shows that the hierarchical network gives a good qualitative representation of the structure of real porous media. Secondly, we study a problem of the transport in a heterogeneous media which structure is evolving during the time. The models where the evolution of the structure is not influenced by the transport are studied in detail. These models present a phase transition of the same nature as that observed on the percolation networks. We propose a new theoretical description of this transition, and we express critical exponents describing the evolution of the conductivity as a function of fundamental exponents of percolation theory. (author) [fr

  4. Cooperative games and network structures

    NARCIS (Netherlands)

    Musegaas, Marieke

    2017-01-01

    This thesis covers various research topics involving cooperative game theory, a mathematical tool to analyze the cooperative behavior within a group of players. The focus is mainly on interrelations between operations research and cooperative game theory by analyzing specific types of cooperative

  5. Complexity in Simplicity: Flexible Agent-based State Space Exploration

    DEFF Research Database (Denmark)

    Rasmussen, Jacob Illum; Larsen, Kim Guldstrand

    2007-01-01

    In this paper, we describe a new flexible framework for state space exploration based on cooperating agents. The idea is to let various agents with different search patterns explore the state space individually and communicate information about fruitful subpaths of the search tree to each other...

  6. A Resource Logic for Multi-Agent Plan Merging

    NARCIS (Netherlands)

    De Weerdt, M.M.; Bos, A.; Tonino, H.; Witteveen, C.

    2003-01-01

    In a multi-agent system, agents are carrying out certain tasks by executing plans. Consequently, the problem of finding a plan, given a certain goal, has been given a lot of attention in the literature. Instead of concentrating on this problem, the focus of this paper is on cooperation between

  7. Does intuition cause cooperation?

    Science.gov (United States)

    Verkoeijen, Peter P J L; Bouwmeester, Samantha

    2014-01-01

    Recently, researchers claimed that people are intuitively inclined to cooperate with reflection causing them to behave selfishly. Empirical support for this claim came from experiments using a 4-player public goods game with a marginal return of 0.5 showing that people contributed more money to a common project when they had to decide quickly (i.e., a decision based on intuition) than when they were instructed to reflect and decide slowly. This intuitive-cooperation effect is of high scientific and practical importance because it argues against a central assumption of traditional economic and evolutionary models. The first experiment of present study was set up to examine the generality of the intuitive-cooperation effect and to further validate the experimental task producing the effect. In Experiment 1, we investigated Amazon Mechanical Turk (AMT) workers' contributions to a 4-player public goods game with a marginal return of 0.5 while we manipulated the knowledge about the other players' contribution to the public goods game (contribution known vs. contribution unknown), the identity of the other players (humans vs. computers randomly generating contributions) and the time constraint (time pressure/intuition vs. forced delay/reflection). However, the results of Experiment 1 failed to reveal an intuitive-cooperation effect. Furthermore, four subsequent direct replications attempts with AMT workers (Experiments 2a, 2b, 2c and Experiment 3, which was conducted with naïve/inexperienced participants) also failed to demonstrate intuitive-cooperation effects. Taken together, the results of the present study could not corroborate the idea that people are intuitively cooperative, hence suggesting that the theoretical relationship between intuition and cooperation should be further scrutinized.

  8. Does intuition cause cooperation?

    Directory of Open Access Journals (Sweden)

    Peter P J L Verkoeijen

    Full Text Available Recently, researchers claimed that people are intuitively inclined to cooperate with reflection causing them to behave selfishly. Empirical support for this claim came from experiments using a 4-player public goods game with a marginal return of 0.5 showing that people contributed more money to a common project when they had to decide quickly (i.e., a decision based on intuition than when they were instructed to reflect and decide slowly. This intuitive-cooperation effect is of high scientific and practical importance because it argues against a central assumption of traditional economic and evolutionary models. The first experiment of present study was set up to examine the generality of the intuitive-cooperation effect and to further validate the experimental task producing the effect. In Experiment 1, we investigated Amazon Mechanical Turk (AMT workers' contributions to a 4-player public goods game with a marginal return of 0.5 while we manipulated the knowledge about the other players' contribution to the public goods game (contribution known vs. contribution unknown, the identity of the other players (humans vs. computers randomly generating contributions and the time constraint (time pressure/intuition vs. forced delay/reflection. However, the results of Experiment 1 failed to reveal an intuitive-cooperation effect. Furthermore, four subsequent direct replications attempts with AMT workers (Experiments 2a, 2b, 2c and Experiment 3, which was conducted with naïve/inexperienced participants also failed to demonstrate intuitive-cooperation effects. Taken together, the results of the present study could not corroborate the idea that people are intuitively cooperative, hence suggesting that the theoretical relationship between intuition and cooperation should be further scrutinized.

  9. Dynamic heterogeneity in life histories

    DEFF Research Database (Denmark)

    Tuljapurkar, Shripad; Steiner, Uli; Orzack, Steven Hecht

    2009-01-01

    or no fixed heterogeneity influences this trait. We propose that dynamic heterogeneity provides a 'neutral' model for assessing the possible role of unobserved 'quality' differences between individuals. We discuss fitness for dynamic life histories, and the implications of dynamic heterogeneity...... generate dynamic heterogeneity: life-history differences produced by stochastic stratum dynamics. We characterize dynamic heterogeneity in a range of species across taxa by properties of the Markov chain: the entropy, which describes the extent of heterogeneity, and the subdominant eigenvalue, which...... distributions of lifetime reproductive success. Dynamic heterogeneity contrasts with fixed heterogeneity: unobserved differences that generate variation between life histories. We show by an example that observed distributions of lifetime reproductive success are often consistent with the claim that little...

  10. Impacts of extension access and cooperative membership on technology adoption and household welfare.

    Science.gov (United States)

    Wossen, Tesfamicheal; Abdoulaye, Tahirou; Alene, Arega; Haile, Mekbib G; Feleke, Shiferaw; Olanrewaju, Adetunji; Manyong, Victor

    2017-08-01

    This paper examines the impacts of access to extension services and cooperative membership on technology adoption, asset ownership and poverty using household-level data from rural Nigeria. Using different matching techniques and endogenous switching regression approach, we find that both extension access and cooperative membership have a positive and statistically significant effect on technology adoption and household welfare. Moreover, we find that both extension access and cooperative membership have heterogeneous impacts. In particular, we find evidence of a positive selection as the average treatment effects of extension access and cooperative membership are higher for farmers with the highest propensity to access extension and cooperative services. The impact of extension services on poverty reduction and of cooperatives on technology adoption is significantly stronger for smallholders with access to formal credit than for those without access. This implies that expanding rural financial markets can maximize the potential positive impacts of extension and cooperative services on farmers' productivity and welfare.

  11. Gender differences in cooperation: experimental evidence on high school students.

    Directory of Open Access Journals (Sweden)

    J Alberto Molina

    Full Text Available The emergence of cooperation among unrelated human subjects is a long-standing conundrum that has been amply studied both theoretically and experimentally. Within the question, a less explored issue relates to the gender dependence of cooperation, which can be traced back to Darwin, who stated that "women are less selfish but men are more competitive". Indeed, gender has been shown to be relevant in several game theoretical paradigms of social cooperativeness, including prisoner's dilemma, snowdrift and ultimatum/dictator games, but there is no consensus as to which gender is more cooperative. We here contribute to this literature by analyzing the role of gender in a repeated Prisoners' Dilemma played by Spanish high-school students in both a square lattice and a heterogeneous network. While the experiment was conducted to shed light on the influence of networks on the emergence of cooperation, we benefit from the availability of a large dataset of more 1200 participants. We applied different standard econometric techniques to this dataset, including Ordinary Least Squares and Linear Probability models including random effects. All our analyses indicate that being male is negatively associated with the level of cooperation, this association being statistically significant at standard levels. We also obtain a gender difference in the level of cooperation when we control for the unobserved heterogeneity of individuals, which indicates that the gender gap in cooperation favoring female students is present after netting out this effect from other socio-demographics factors not controlled for in the experiment, and from gender differences in risk, social and competitive preferences.

  12. 9th KES Conference on Agent and Multi-Agent Systems : Technologies and Applications

    CERN Document Server

    Howlett, Robert; Jain, Lakhmi

    2015-01-01

    Agents and multi-agent systems are related to a modern software paradigm which has long been recognized as a promising technology for constructing autonomous, complex and intelligent systems. The topics covered in this volume include agent-oriented software engineering, agent co-operation, co-ordination, negotiation, organization and communication, distributed problem solving, specification of agent communication languages, agent privacy, safety and security, formalization of ontologies and conversational agents. The volume highlights new trends and challenges in agent and multi-agent research and includes 38 papers classified in the following specific topics: learning paradigms, agent-based modeling and simulation, business model innovation and disruptive technologies, anthropic-oriented computing, serious games and business intelligence, design and implementation of intelligent agents and multi-agent systems, digital economy, and advances in networked virtual enterprises. Published p...

  13. Distributed, cooperating knowledge-based systems

    Science.gov (United States)

    Truszkowski, Walt

    1991-01-01

    Some current research in the development and application of distributed, cooperating knowledge-based systems technology is addressed. The focus of the current research is the spacecraft ground operations environment. The underlying hypothesis is that, because of the increasing size, complexity, and cost of planned systems, conventional procedural approaches to the architecture of automated systems will give way to a more comprehensive knowledge-based approach. A hallmark of these future systems will be the integration of multiple knowledge-based agents which understand the operational goals of the system and cooperate with each other and the humans in the loop to attain the goals. The current work includes the development of a reference model for knowledge-base management, the development of a formal model of cooperating knowledge-based agents, the use of testbed for prototyping and evaluating various knowledge-based concepts, and beginning work on the establishment of an object-oriented model of an intelligent end-to-end (spacecraft to user) system. An introductory discussion of these activities is presented, the major concepts and principles being investigated are highlighted, and their potential use in other application domains is indicated.

  14. The tritium labeling of Butibufen by heterogeneous catalytic exchange

    International Nuclear Information System (INIS)

    Santamaria, J.; Rebollo, D.

    1986-01-01

    The labeling of a new non-steroidal antiinflammatory agent, Butibufen (2-(4-isobutylphenyl) butyric acid) was studied. The method used was heterogeneous catalytic exchange between Butibufen and tritiated water, obtained in situ. Purification was accomplished through thin layer chromatography. Concentration, purity and specific activity of the labeled drug were determined by ultraviolet and liquid scintillation techniques. (Author) 7 refs

  15. Managing heterogeneous and unanchored expectations: a monetary policy analysis

    NARCIS (Netherlands)

    Hommes, C.; Lustenhouwer, J.

    2016-01-01

    We study monetary policy in a New Keynesian model with heterogeneity in expectations. Agents may choose from a continuum of forecasting rules and adjust their expectations based on relative past performance. The extent to which expectations are anchored to the fundamentals of the economy turns out

  16. Accounting for Heterogeneous Returns in Sequential Schooling Decisions

    NARCIS (Netherlands)

    Zamarro, G.

    2006-01-01

    This paper presents a method for estimating returns to schooling that takes into account that returns may be heterogeneous among agents and that educational decisions are made sequentially.A sequential decision model is interesting because it explicitly considers that the level of education of each

  17. Genetic heterogeneity of retinitis pigmentosa

    OpenAIRE

    Hartono, Hartono

    2015-01-01

    Genetic heterogeneity is a phenomenon in which a genetic disease can be transmitted by several modes of inheritance. The understanding of genetic heterogeneity is important in giving genetic counselling.The presence of genetic heterogeneity can be explained by the existence of:1.different mutant alleles at a single locus, and2.mutant alleles at different loci affecting the same enzyme or protein, or affecting different enzymes or proteins.To have an overall understanding of genetic heterogene...

  18. Cooperation in Construction:

    DEFF Research Database (Denmark)

    Vogelius, Peter; Storgaard, Kresten

    2016-01-01

    The study presents a building project executed by a major Danish construction company, where cooperation and its staging were essential for achieving high productivity and competitiveness. The form of this cooperation is the main theme for the article. The contractor actively changed the communic......The study presents a building project executed by a major Danish construction company, where cooperation and its staging were essential for achieving high productivity and competitiveness. The form of this cooperation is the main theme for the article. The contractor actively changed...... the companies in the case can be understood as possessing a social capital which is enforced and united by initiatives of the main contractor. The social capital was built up and maintained through the actual constitution of cooperation already in the initial phase of bidding before the building process....... The management logic of the main contractor is interpreted as based on a sociology-inspired understanding focusing on norms and social values rather than on contractual (law) and functional (engineering) logic, which had hitherto been prevalent in Danish construction management....

  19. The story of technical cooperation

    International Nuclear Information System (INIS)

    Park, Yang Taek

    1989-09-01

    This book gives descriptions of technical cooperation, which is about why does technology transfer?, process of technology transfer with model, decisive cause and cooperation of technology transfer, cost and effect of technology transfer, historical experience of technology transfer, cases of technology transfer by field such as rubber tire, medicine and computer industry and automobile industry, technology transfer process and present condition of technical cooperation, and strategy for rising of technical cooperation : selection of technology for object of cooperation and development of human resources.

  20. Cooper Pairs in Insulators?

    International Nuclear Information System (INIS)

    Valles, James

    2008-01-01

    Nearly 50 years elapsed between the discovery of superconductivity and the emergence of the microscopic theory describing this zero resistance state. The explanation required a novel phase of matter in which conduction electrons joined in weakly bound pairs and condensed with other pairs into a single quantum state. Surprisingly, this Cooper pair formation has also been invoked to account for recently uncovered high-resistance or insulating phases of matter. To address this possibility, we have used nanotechnology to create an insulating system that we can probe directly for Cooper pairs. I will present the evidence that Cooper pairs exist and dominate the electrical transport in these insulators and I will discuss how these findings provide new insight into superconductor to insulator quantum phase transitions.

  1. Evolution, epigenetics and cooperation.

    Science.gov (United States)

    Bateson, Patrick

    2014-04-01

    Explanations for biological evolution in terms of changes in gene frequencies refer to outcomes rather than process. Integrating epigenetic studies with older evolutionary theories has drawn attention to the ways in which evolution occurs. Adaptation at the level of the gene is givingway to adaptation at the level of the organism and higher-order assemblages of organisms. These ideas impact on the theories of how cooperation might have evolved. Two of the theories, i.e. that cooperating individuals are genetically related or that they cooperate for self-interested reasons, have been accepted for a long time. The idea that adaptation takes place at the level of groups is much more controversial. However, bringing together studies of development with those of evolution is taking away much of the heat in the debate about the evolution of group behaviour.

  2. Cooperative Prototyping Experiments

    DEFF Research Database (Denmark)

    Bødker, Susanne; Grønbæk, Kaj

    1989-01-01

    This paper describes experiments with a design technique that we denote cooperative prototyping. The experiments consider design of a patient case record system for municipal dental clinics in which we used HyperCard, an off the shelf programming environment for the Macintosh. In the ecperiments we...... tried to achieve a fluent work-like evaluation of prototypes where users envisioned future work with a computer tool, at the same time as we made on-line modifications of prototypes in cooperation with the users when breakdown occur in their work-like evaluation. The experiments showed...... that it was possible to make a number of direct manipulation changes of prototypes in cooperation with the users, in interplay with their fluent work-like evaluation of these. However, breakdown occurred in the prototyping process when we reached the limits of the direct manipulation support for modification. From...

  3. Cooperative peer-to-peer multiagent-based systems.

    Science.gov (United States)

    Caram, L F; Caiafa, C F; Ausloos, M; Proto, A N

    2015-08-01

    A multiagent based model for a system of cooperative agents aiming at growth is proposed. This is based on a set of generalized Verhulst-Lotka-Volterra differential equations. In this study, strong cooperation is allowed among agents having similar sizes, and weak cooperation if agents have markedly different "sizes", thus establishing a peer-to-peer modulated interaction scheme. A rigorous analysis of the stable configurations is presented first examining the fixed points of the system, next determining their stability as a function of the model parameters. It is found that the agents are self-organizing into clusters. Furthermore, it is demonstrated that, depending on parameter values, multiple stable configurations can coexist. It occurs that only one of them always emerges with probability close to one, because its associated attractor dominates over the rest. This is shown through numerical integrations and simulations, after analytic developments. In contrast to the competitive case, agents are able to increase their capacity beyond the no-interaction case limit. In other words, when some collaborative partnership among a relatively small number of partners takes place, all agents act in good faith prioritizing the common good, when receiving a mutual benefit allowing them to surpass their capacity.

  4. Interactive diversity promotes the evolution of cooperation in structured populations

    International Nuclear Information System (INIS)

    Su, Qi; Li, Aming; Zhou, Lei; Wang, Long

    2016-01-01

    Evolutionary games on networks traditionally assume that each individual adopts an identical strategy to interact with all its neighbors in each generation. Considering the prevalent diversity of individual interactions in the real society, here we propose the concept of interactive diversity, which allows individuals to adopt different strategies against different neighbors in each generation. We investigate the evolution of cooperation based on the edge dynamics rather than the traditional nodal dynamics in networked systems. The results show that, without invoking any other mechanisms, interactive diversity drives the frequency of cooperation to a high level for a wide range of parameters in both well-mixed and structured populations. Even in highly connected populations, cooperation still thrives. When interactive diversity and large topological heterogeneity are combined together, however, in the relaxed social dilemma, cooperation level is lower than that with just one of them, implying that the combination of many promotive factors may make a worse outcome. By an analytical approximation, we get the condition under which interactive diversity provides more advantages for cooperation than traditional evolutionary dynamics does. Numerical simulations validating the approximation are also presented. Our work provides a new line to explore the latent relation between the ubiquitous cooperation and individuals’ distinct responses in different interactions. The presented results suggest that interactive diversity should receive more attention in pursuing mechanisms fostering cooperation. (paper)

  5. Agent-Based Models in Social Physics

    Science.gov (United States)

    Quang, Le Anh; Jung, Nam; Cho, Eun Sung; Choi, Jae Han; Lee, Jae Woo

    2018-06-01

    We review the agent-based models (ABM) on social physics including econophysics. The ABM consists of agent, system space, and external environment. The agent is autonomous and decides his/her behavior by interacting with the neighbors or the external environment with the rules of behavior. Agents are irrational because they have only limited information when they make decisions. They adapt using learning from past memories. Agents have various attributes and are heterogeneous. ABM is a non-equilibrium complex system that exhibits various emergence phenomena. The social complexity ABM describes human behavioral characteristics. In ABMs of econophysics, we introduce the Sugarscape model and the artificial market models. We review minority games and majority games in ABMs of game theory. Social flow ABM introduces crowding, evacuation, traffic congestion, and pedestrian dynamics. We also review ABM for opinion dynamics and voter model. We discuss features and advantages and disadvantages of Netlogo, Repast, Swarm, and Mason, which are representative platforms for implementing ABM.

  6. Econophysics of agent-based models

    CERN Document Server

    Aoyama, Hideaki; Chakrabarti, Bikas; Chakraborti, Anirban; Ghosh, Asim

    2014-01-01

    The primary goal of this book is to present the research findings and conclusions of physicists, economists, mathematicians and financial engineers working in the field of "Econophysics" who have undertaken agent-based modelling, comparison with empirical studies and related investigations. Most standard economic models assume the existence of the representative agent, who is “perfectly rational” and applies the utility maximization principle when taking action. One reason for this is the desire to keep models mathematically tractable: no tools are available to economists for solving non-linear models of heterogeneous adaptive agents without explicit optimization. In contrast, multi-agent models, which originated from statistical physics considerations, allow us to go beyond the prototype theories of traditional economics involving the representative agent. This book is based on the Econophys-Kolkata VII Workshop, at which many such modelling efforts were presented. In the book, leading researchers in the...

  7. International co-operation

    International Nuclear Information System (INIS)

    1997-01-01

    In 1996, Nuclear Regulatory Authority of the Slovak Republic (NRA SR) ensured the Slovak Republic (SR) obligations with relation to the international agreements and with the SR membership in the IAEA.International co-operation has been ensured on the basis of the bilateral international agreements. With the Ministry of Foreign Affairs co-operation, the SR fulfilled its financial obligations to this organization in due time and in the full scope. Representing Central and Eastern Europe interest in the Board of Governors, the SR participation in the highest executive in the highest executive authority was finished in 1996.The Board of Governors Vice-chairman position was executed by NRA SR Chairman. 5 national and 6 regional technical co-operation and assistance projects were realized in 1996. 12 organizations participated in these projects and accordingly 104 experts took part in training programmes, scientific visits or as the mission members abroad. Besides, Slovak experts participated at work of technical advisory and consultation groups with the significant assistance. In the framework of IAEA co-operation, the SR was visited by 11 expert missions formed by 28 experts from 19 countries including IAEA. Slovak organizations, namely institutes of the Academy of Sciences, Slovak research centres and universities participated in IAEA scientific and research activities through NRA SR. 15 scientific contracts in total were approved and realized and these contracts are utilized as supplementary financing of the own scientific and research projects. Other international co-operation and regional co-operation activities of the NRA SR in 1996 are reviewed

  8. Heuristics guide cooperative behaviors in public goods game

    Science.gov (United States)

    Wang, Yongjie; Chen, Tong

    2015-12-01

    In public goods game (PGG), player's cooperative behavior is not pure economical rationality, but social preference and prosocial intuition play extremely important roles as well. Social preference and prosocial intuition can be guided by heuristics from one's neighbors in daily life. To better investigate the impacts of heuristics on the evolution of cooperation, four types of agents are introduced into our spatial PGG. Through numerical simulations, results show that the larger percentages of cooperators with independent thought, the easier emergence and maintenance of collective cooperative behaviors. Additionally, we find that differentia heuristic capability has great effect on the equilibrium of PGG. Cooperation can be obviously promoted, when heuristic capability of cooperators with independent thought is stronger than that of defectors with independent thought. Finally, we observe that cooperators with independent thought and defectors with independent thought are favorable for the formation of some high quality clusters, which can resist the invasion between each other. Our work may help us understand more clearly the mechanism of cooperation in real world.

  9. Internet-enabled collaborative agent-based supply chains

    Science.gov (United States)

    Shen, Weiming; Kremer, Rob; Norrie, Douglas H.

    2000-12-01

    This paper presents some results of our recent research work related to the development of a new Collaborative Agent System Architecture (CASA) and an Infrastructure for Collaborative Agent Systems (ICAS). Initially being proposed as a general architecture for Internet based collaborative agent systems (particularly complex industrial collaborative agent systems), the proposed architecture is very suitable for managing the Internet enabled complex supply chain for a large manufacturing enterprise. The general collaborative agent system architecture with the basic communication and cooperation services, domain independent components, prototypes and mechanisms are described. Benefits of implementing Internet enabled supply chains with the proposed infrastructure are discussed. A case study on Internet enabled supply chain management is presented.

  10. Membership in cooperative societies

    Directory of Open Access Journals (Sweden)

    Eba Gaminde Egia

    2017-12-01

    Full Text Available In this work we will analyze the practical application of one of the cooperative principles, «voluntary and free membership», referring to the entering of members in cooperative societies. We will first explain the meaning of this principle, and then bring up its normative regulation, with special emphasis on those aspects in which our autonomic laws differ, and ending with a brief reference to the economic aspect and the different ways to make contributions and their consequences.Received: 31 May 2017Accepted: 14 October 2017Published online: 22 December 2017

  11. Introduction: cooperative learning

    Directory of Open Access Journals (Sweden)

    José-Manuel Serrano

    2014-10-01

    Full Text Available The principal objective of this revision is the recognition of cooperative learning as a highly effective strategy for the accomplishment of the general goals in learning. The different investigations assessed validate the potential that a cooperative organization of the classroom could entail for academic achievement, self-esteem, interpersonal attraction or social support. The solidity of the existing research contributes to its external and internal validity and, thus, to conclude that the results are consistent and can be extrapolated to different cultures, ethnic groups or countries.

  12. Excited cooper pairs

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Arrietea, M. G.; Solis, M. A.; De Llano, M. [Universidad Nacional Autonoma de Mexico, Mexico, D.F (Mexico)

    2001-02-01

    Excited cooper pairs formed in a many-fermion system are those with nonzero total center-of mass momentum (CMM). They are normally neglected in the standard Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity for being too few compared with zero CMM pairs. However, a Bose-Einstein condensation picture requires both zero and nonzero CMM pairs. Assuming a BCS model interaction between fermions we determine the populations for all CMM values of Cooper pairs by actually calculating the number of nonzero-CMM pairs relative to that of zero-CMM ones in both 2D and 3D. Although this ratio decreases rapidly with CMM, the number of Cooper pairs for any specific CMM less than the maximum (or breakup of the pair) momentum turns out to be typically larger than about 95% of those with zero-CMM at zero temperature T. Even at T {approx}100 K this fraction en 2D is still as large as about 70% for typical quasi-2D cuprate superconductor parameters. [Spanish] Los pares de cooper excitados formados en un sistema de muchos electrones, son aquellos con momentos de centro de masa (CMM) diferente de cero. Normalmente estos no son tomados en cuenta en la teoria estandar de la superconductividad de Bardeen-Cooper-Schrieffer (BCS) al suponer que su numero es muy pequeno comparados con los pares de centro de masa igual a cero. Sin embargo, un esquema de condensacion Bose-Einstein requiere de ambos pares, con CMM cero y diferente de cero. Asumiendo una interaccion modelo BCS entre los fermiones, determinamos la poblacion de pares cooper con cada uno de todos los posibles valores del CMM calculando el numero de pares con momentos de centro de masa diferente de cero relativo a los pares de CMM igual a cero, en 2D y 3D. Aunque esta razon decrece rapidamente con el CMM, el numero de pares de cooper para cualquier CMM especifico menor que el momento maximo (o rompimiento de par) es tipicamente mas grande que el 95% de aquellos con CMM cero. Aun a T {approx}100 K esta fraccion en 2D es

  13. Heterogeneous chromatin target model

    International Nuclear Information System (INIS)

    Watanabe, Makoto

    1996-01-01

    The higher order structure of the entangled chromatin fibers in a chromosome plays a key role in molecular control mechanism involved in chromosome mutation due to ionizing radiations or chemical mutagens. The condensed superstructure of chromatin is not so rigid and regular as has been postulated in general. We have proposed a rheological explanation for the flexible network system ('chromatin network') that consists of the fluctuating assembly of nucleosome clusters linked with supertwisting DNA in a chromatin fiber ('Supertwisting Particulate Model'). We have proposed a 'Heterosensitive Target Model' for cellular radiosensitivity that is a modification of 'Heterogeneous Target Model'. The heterogeneity of chromatin target is derived from the highly condensed organization of chromatin segments consist of unstable and fragile sites in the fluctuating assembly of nucleosome clusters, namely 'supranucleosomal particles' or 'superbeads'. The models have been principally supported by our electron microscopic experiments employing 'surface - spreading whole - mount technique' since 1967. However, some deformation and artifacts in the chromatin structure are inevitable with these electron microscopic procedures. On the contrary, the 'atomic force microscope (AFM)' can be operated in liquid as well as in the air. A living specimen can be examined without any preparative procedures. Micromanipulation of the isolated chromosome is also possible by the precise positional control of a cantilever on the nanometer scale. The living human chromosomes were submerged in a solution of culture medium and observed by AFM using a liquid immersion cell. The surface - spreading whole - mount technique was applicable for this observation. The particulate chromatin segments of nucleosome clusters were clearly observed within mitotic human chromosomes in a living hydrated condition. These findings support the heterogeneity of chromatin target in a living cell. (J.P.N.)

  14. Support for cooperative control and maintenance operation in advanced nuclear power plant from generalized and intuitive viewpoints

    International Nuclear Information System (INIS)

    Numano, Masayoshi; Niwa, Yasuyuki; Miyazaki, Keiko; Fukuto, Junji; Tanaka, Kunihiko; Okazaki, Tadatsugi; Itoh, Hiroko; Matsuoka, Takeshi

    2002-01-01

    To keep safety and effectiveness in control and maintenance operations of large and complex plants like nuclear power plants, cooperative operation among human and machine agents is proposed. The concept is that the cooperation augments human capability as an individual by closely related team members with adequate interfaces. This paper describes a basic concept of the cooperation, necessary interface functions, infrastructure of the cooperation and communication logging for accumulation and sharing of knowledge. (author)

  15. Heterogeneous Active Matter

    Science.gov (United States)

    Kolb, Thomas; Klotsa, Daphne

    Active systems are composed of self-propelled (active) particles that locally convert energy into motion and exhibit emergent collective behaviors, such as fish schooling and bird flocking. Most works so far have focused on monodisperse, one-component active systems. However, real systems are heterogeneous, and consist of several active components. We perform molecular dynamics simulations of multi-component active matter systems and report on their emergent behavior. We discuss the phase diagram of dynamic states as well as parameters where we see mixing versus segregation.

  16. Effect of information transmission on cooperative behavior

    International Nuclear Information System (INIS)

    Sun Jintu; Wang Yinghai; Wang Shengjun; Huang Zigang; Yang Lei; Do, Younghae

    2010-01-01

    Considering the fact, in the real world, that information is transmitted with a time delay, we study an evolutionary spatial prisoner's dilemma game where agents update strategies according to certain information that they have learned. In our study, the game dynamics are classified by the modes of information learning as well as game interaction, and four different combinations, i.e. the mean-field case, case I, case II and local case, are studied comparatively. It is found that the time delay in case II smoothes the phase transition from the absorbing states of C (or D) to their mixing state, and promotes cooperation for most parameter values. Our work provides insights into the temporal behavior of information and the memory of the system, and may be helpful in understanding the cooperative behavior induced by the time delay in social and biological systems.

  17. Cooperatives between truth and validity

    Directory of Open Access Journals (Sweden)

    Guilherme Krueger

    2014-12-01

    Full Text Available The current declaration of the International Cooperative Alliance on cooperative identity since its 1995 Centennial Conference (which was held in Manchester makes no distinction between cooperation and cooperative. The lack of distinction between cooperation and cooperative has caused the Decennial Cooperative Action Plan to define cooperatives as a form, while their materiality is regarded as managerial: a business (activity under a cooperative form. An identity that is close to us cannot be reduced to form, without this being a problem. Therefore, the value underlying this identity —cooperation— must have a substantial basis, even if it is idealised, if it is to affect us.Received: 27.03.2014Accepted: 12.05.2014

  18. Social penalty promotes cooperation in a cooperative society.

    Science.gov (United States)

    Ito, Hiromu; Yoshimura, Jin

    2015-08-04

    Why cooperation is well developed in human society is an unsolved question in biological and human sciences. Vast studies in game theory have revealed that in non-cooperative games selfish behavior generally dominates over cooperation and cooperation can be evolved only under very limited conditions. These studies ask the origin of cooperation; whether cooperation can evolve in a group of selfish individuals. In this paper, instead of asking the origin of cooperation, we consider the enhancement of cooperation in a small already cooperative society. We ask whether cooperative behavior is further promoted in a small cooperative society in which social penalty is devised. We analyze hawk-dove game and prisoner's dilemma introducing social penalty. We then expand it for non-cooperative games in general. The results indicate that cooperation is universally favored if penalty is further imposed. We discuss the current result in terms of the moral, laws, rules and regulations in a society, e.g., criminology and traffic violation.

  19. Imitating Cooperation and the Formation of long-term Relationships

    DEFF Research Database (Denmark)

    Schumacher, Heiner

    2013-01-01

    We study the infinitely repeated prisoner’s dilemma with the option to maintain or to quit relationships. We show that if agents imitate successful strategies infrequently, defection is not dynamically stable and cooperation emerges regardless of the initial distribution of strategies....

  20. Cooperative social capital

    Directory of Open Access Journals (Sweden)

    Oscar Acera Manero

    2005-12-01

    Full Text Available Social capital consists of the contributions of members and associates, both mandatory and voluntary. From an accounting point of view, it is a liability figure that expresses the value of a portion of the equity of the cooperative. Its inclusion in the liability is not the fact that it is a debt but by its nature unenforceable.

  1. Supranational Cooperation in Europe

    NARCIS (Netherlands)

    de Deugd, Nienke; Stamm, Katharina; Westerman, Wim

    The sovereign debt crisis and the euro crisis have prompted heads of state and government in Europe to intensify supranational cooperation. However, some political leaders and policy makers aim for more. They propose the introduction of a common European economic government that would prevent Europe

  2. Systematic, Cooperative Evaluation.

    Science.gov (United States)

    Nassif, Paula M.

    Evaluation procedures based on a systematic evaluation methodology, decision-maker validity, new measurement and design techniques, low cost, and a high level of cooperation on the part of the school staff were used in the assessment of a public school mathematics program for grades 3-8. The mathematics curriculum was organized into Spirals which…

  3. Non-Cooperative Games

    NARCIS (Netherlands)

    van Damme, E.E.C.

    2014-01-01

    We describe non-cooperative game models and discuss game theoretic solution concepts. Some applications are also noted. Conventional theory focuses on the question ‘how will rational players play?’, and has the Nash equilibrium at its core. We discuss this concept and its interpretations, as well as

  4. Cooperative Technolgy Deployed

    NARCIS (Netherlands)

    Koenders, E.; Velt, R. in 't

    2011-01-01

    After the successful demonstrations of cooperative technology by the CVIS and Safespot projects the question remains how this technology can be successfully deployed. This question is explored by the Field Operational Test project FREILOT, which aims to provide fuel economy applications that must be

  5. Cooper's Hawk (Accipiter cooperii)

    Science.gov (United States)

    Jean-Luc E. Cartron; Patricia L. Kennedy; Rob Yaksich; Scott H. Stoleson

    2010-01-01

    The Cooper's Hawk (Accipiter cooperii) is intermediate in size between the Northern Goshawk (Accipiter gentilis) and the Sharp-shinned Hawk (A. striatus), northern North America's other two accipiters. The two sexes are almost alike in plumage, but as in both of the other species, the female is noticeably larger. According to Wheeler and Clark (1995), a...

  6. Cooperative courseware authoring support

    NARCIS (Netherlands)

    Dicheva, D.; Aroyo, L.M.; Cristea, A.I.

    2003-01-01

    We refined our knowledge classification and indexing approach applied in our previously developed system AIMS (Agentbased Information Management System) by introducing ontology-oriented support for cooperative courseware authoring. In order to provide a basis for formal semantics and reasoning in

  7. Can war foster cooperation?

    Czech Academy of Sciences Publication Activity Database

    Bauer, Michal; Blattman, C.; Chytilová, Julie; Henrich, J.; Miguel, E.; Mitts, T.

    2016-01-01

    Roč. 30, č. 3 (2016), s. 249-274 ISSN 0895-3309 R&D Projects: GA ČR(CZ) GBP402/12/G130 Institutional support: RVO:67985998 Keywords : war * conflict * cooperation Subject RIV: AH - Economics Impact factor: 5.727, year: 2016

  8. Robust Dynamic Cooperative Games

    NARCIS (Netherlands)

    Bauso, D.; Timmer, Judith B.

    2006-01-01

    Classical cooperative game theory is no longer a suitable tool for those situations where the values of coalitions are not known with certainty. Recent works address situations where the values of coalitions are modelled by random variables. In this work we still consider the values of coalitions as

  9. Does intuition cause cooperation?

    NARCIS (Netherlands)

    P.P.J.L. Verkoeijen (Peter); S. Bouwmeester (Samantha)

    2014-01-01

    textabstractRecently, researchers claimed that people are intuitively inclined to cooperate with reflection causing them to behave selfishly. Empirical support for this claim came from experiments using a 4-player public goods game with a marginal return of 0.5 showing that people contributed more

  10. Indian Ocean Rim Cooperation

    DEFF Research Database (Denmark)

    Wippel, Steffen

    Since the mid-1990s, the Indian Ocean has been experiencing increasing economic cooperation among its rim states. Middle Eastern countries, too, participate in the work of the Indian Ocean Rim Association, which received new impetus in the course of the current decade. Notably Oman is a very active...

  11. Predicting Human Cooperation.

    Directory of Open Access Journals (Sweden)

    John J Nay

    Full Text Available The Prisoner's Dilemma has been a subject of extensive research due to its importance in understanding the ever-present tension between individual self-interest and social benefit. A strictly dominant strategy in a Prisoner's Dilemma (defection, when played by both players, is mutually harmful. Repetition of the Prisoner's Dilemma can give rise to cooperation as an equilibrium, but defection is as well, and this ambiguity is difficult to resolve. The numerous behavioral experiments investigating the Prisoner's Dilemma highlight that players often cooperate, but the level of cooperation varies significantly with the specifics of the experimental predicament. We present the first computational model of human behavior in repeated Prisoner's Dilemma games that unifies the diversity of experimental observations in a systematic and quantitatively reliable manner. Our model relies on data we integrated from many experiments, comprising 168,386 individual decisions. The model is composed of two pieces: the first predicts the first-period action using solely the structural game parameters, while the second predicts dynamic actions using both game parameters and history of play. Our model is successful not merely at fitting the data, but in predicting behavior at multiple scales in experimental designs not used for calibration, using only information about the game structure. We demonstrate the power of our approach through a simulation analysis revealing how to best promote human cooperation.

  12. Discover new cooperation forms

    International Nuclear Information System (INIS)

    Anon.

    2000-01-01

    In spite of the good forecasts concerning the supply and demand, the gas market is full of uncertainties because of the competition and the industrial reorganizing. Producers and operators try to define new forms of cooperation allowing the attainments protection and at the same time allowing to take advantage of the market opportunities with a shared risk. (A.L.B.)

  13. International co-operation

    International Nuclear Information System (INIS)

    1998-01-01

    A brief account of activities in international co-operation carried out by the Nuclear power plants Jaslovske Bohunice in 1997 is presented. Professionality of the Bohunice NPPs staff was highly appreciated by inviting them to be the OSART team members

  14. Marketing co-operatives

    NARCIS (Netherlands)

    G.W.J. Hendrikse (George); C.P. Veerman (Cees)

    2000-01-01

    textabstractMarketing co-operatives (MCs) are analysed from an incomplete contracting perspective. The requirement of the domination of control by the members of a MC is a threat to the survival of a MC in markets where the level of asset specificity at the processing stage of production is

  15. Hierarchical unilamellar vesicles of controlled compositional heterogeneity.

    Directory of Open Access Journals (Sweden)

    Maik Hadorn

    Full Text Available Eukaryotic life contains hierarchical vesicular architectures (i.e. organelles that are crucial for material production and trafficking, information storage and access, as well as energy production. In order to perform specific tasks, these compartments differ among each other in their membrane composition and their internal cargo and also differ from the cell membrane and the cytosol. Man-made structures that reproduce this nested architecture not only offer a deeper understanding of the functionalities and evolution of organelle-bearing eukaryotic life but also allow the engineering of novel biomimetic technologies. Here, we show the newly developed vesicle-in-water-in-oil emulsion transfer preparation technique to result in giant unilamellar vesicles internally compartmentalized by unilamellar vesicles of different membrane composition and internal cargo, i.e. hierarchical unilamellar vesicles of controlled compositional heterogeneity. The compartmentalized giant unilamellar vesicles were subsequently isolated by a separation step exploiting the heterogeneity of the membrane composition and the encapsulated cargo. Due to the controlled, efficient, and technically straightforward character of the new preparation technique, this study allows the hierarchical fabrication of compartmentalized giant unilamellar vesicles of controlled compositional heterogeneity and will ease the development of eukaryotic cell mimics that resemble their natural templates as well as the fabrication of novel multi-agent drug delivery systems for combination therapies and complex artificial microreactors.

  16. [Social cooperatives in Italy].

    Science.gov (United States)

    Villotti, P; Zaniboni, S; Fraccaroli, F

    2014-06-01

    This paper describes the role of social cooperatives in Italy as a type of economic, non-profit organization and their role in contributing to the economic and social growth of the country. The purpose of this paper is to learn more about the experience of the Italian social cooperatives in promoting the work integration process of disadvantaged workers, especially those suffering from mental disorders, from a theoretical and an empirical point of view. Social enterprise is the most popular and consolidated legal and organizational model for social enterprises in Italy, introduced by Law 381/91. Developed during the early 1980s, and formally recognized by law in the early 1990s, social cooperatives aim at pursuing the general interest of the community to promote the human needs and social inclusion of citizens. They are orientated towards aims that go beyond the interest of the business owners, the primary beneficiary of their activities is the community, or groups of disadvantaged people. In Italy, Law 381/91 distinguishes between two categories of social cooperatives, those producing goods of social utility, such as culture, welfare and educational services (A-type), and those providing economic activities for the integration of disadvantaged people into employment (B-type). The main purpose of B-type social cooperatives is to integrate disadvantaged people into the open labour market. This goal is reached after a period of training and working experience inside the firm, during which the staff works to improve both the social and professional abilities of disadvantaged people. During the years, B-type social co-ops acquired a particular relevance in the care of people with mental disorders by offering them with job opportunities. Having a job is central in the recovery process of people suffering from mental diseases, meaning that B-type social co-ops in Italy play an important rehabilitative and integrative role for this vulnerable population of workers. The

  17. Intratumor heterogeneity alters most effective drugs in designed combinations.

    Science.gov (United States)

    Zhao, Boyang; Hemann, Michael T; Lauffenburger, Douglas A

    2014-07-22

    The substantial spatial and temporal heterogeneity observed in patient tumors poses considerable challenges for the design of effective drug combinations with predictable outcomes. Currently, the implications of tissue heterogeneity and sampling bias during diagnosis are unclear for selection and subsequent performance of potential combination therapies. Here, we apply a multiobjective computational optimization approach integrated with empirical information on efficacy and toxicity for individual drugs with respect to a spectrum of genetic perturbations, enabling derivation of optimal drug combinations for heterogeneous tumors comprising distributions of subpopulations possessing these perturbations. Analysis across probabilistic samplings from the spectrum of various possible distributions reveals that the most beneficial (considering both efficacy and toxicity) set of drugs changes as the complexity of genetic heterogeneity increases. Importantly, a significant likelihood arises that a drug selected as the most beneficial single agent with respect to the predominant subpopulation in fact does not reside within the most broadly useful drug combinations for heterogeneous tumors. The underlying explanation appears to be that heterogeneity essentially homogenizes the benefit of drug combinations, reducing the special advantage of a particular drug on a specific subpopulation. Thus, this study underscores the importance of considering heterogeneity in choosing drug combinations and offers a principled approach toward designing the most likely beneficial set, even if the subpopulation distribution is not precisely known.

  18. A User Cooperation Stimulating Strategy Based on Cooperative Game Theory in Cooperative Relay Networks

    Directory of Open Access Journals (Sweden)

    Ping Zhang

    2009-01-01

    Full Text Available This paper proposes a user cooperation stimulating strategy among rational users. The strategy is based on cooperative game theory and enacted in the context of cooperative relay networks. Using the pricing-based mechanism, the system is modeled initially with two nodes and a Base Station (BS. Within this framework, each node is treated as a rational decision maker. To this end, each node can decide whether to cooperate and how to cooperate. Cooperative game theory assists in providing an optimal system utility and provides fairness among users. Under different cooperative forwarding modes, certain questions are carefully investigated, including “what is each node's best reaction to maximize its utility?” and “what is the optimal reimbursement to encourage cooperation?” Simulation results show that the nodes benefit from the proposed cooperation stimulating strategy in terms of utility and thus justify the fairness between each user.

  19. A User Cooperation Stimulating Strategy Based on Cooperative Game Theory in Cooperative Relay Networks

    Directory of Open Access Journals (Sweden)

    Jiang Fan

    2009-01-01

    Full Text Available This paper proposes a user cooperation stimulating strategy among rational users. The strategy is based on cooperative game theory and enacted in the context of cooperative relay networks. Using the pricing-based mechanism, the system is modeled initially with two nodes and a Base Station (BS. Within this framework, each node is treated as a rational decision maker. To this end, each node can decide whether to cooperate and how to cooperate. Cooperative game theory assists in providing an optimal system utility and provides fairness among users. Under different cooperative forwarding modes, certain questions are carefully investigated, including "what is each node's best reaction to maximize its utility?" and "what is the optimal reimbursement to encourage cooperation?" Simulation results show that the nodes benefit from the proposed cooperation stimulating strategy in terms of utility and thus justify the fairness between each user.

  20. Non cooperative games applied to nuclear safeguards

    International Nuclear Information System (INIS)

    Goutal, P.

    1997-01-01

    This study presents the utilization of the non cooperative games in the nuclear safeguards. In order to dissuade from possible diversions of nuclear materials, an inspector has to realize a certain number of inspections in a nuclear installation. The inspector has to minimize the detection time of a diversion and the diverter has to maximize this time. A software, JADIS, is realized to obtain optimum inspection strategy for a great number of periods. Another game is studied: the infiltration game. An infiltration agent has to brake into the installation without being headed off. (A.L.B.)

  1. Cooperative Group Performance in Graduate Research Methodology Courses: The Role of Study Coping and Examination-Taking Coping Strategies

    Science.gov (United States)

    Jiao, Qun G.; Collins, Kathleen M. T.; Onwuegbuzie, Anthony J.

    2013-01-01

    This study seeks to examine the extent to which cooperative group members' levels of coping strategies (study and examination-taking coping strategies) and the degree that heterogeneity (variability of study coping strategies and examination-taking coping strategies) predict cooperative groups' levels of achievement in research methodology…

  2. Large epidemic thresholds emerge in heterogeneous networks of heterogeneous nodes

    Science.gov (United States)

    Yang, Hui; Tang, Ming; Gross, Thilo

    2015-08-01

    One of the famous results of network science states that networks with heterogeneous connectivity are more susceptible to epidemic spreading than their more homogeneous counterparts. In particular, in networks of identical nodes it has been shown that network heterogeneity, i.e. a broad degree distribution, can lower the epidemic threshold at which epidemics can invade the system. Network heterogeneity can thus allow diseases with lower transmission probabilities to persist and spread. However, it has been pointed out that networks in which the properties of nodes are intrinsically heterogeneous can be very resilient to disease spreading. Heterogeneity in structure can enhance or diminish the resilience of networks with heterogeneous nodes, depending on the correlations between the topological and intrinsic properties. Here, we consider a plausible scenario where people have intrinsic differences in susceptibility and adapt their social network structure to the presence of the disease. We show that the resilience of networks with heterogeneous connectivity can surpass those of networks with homogeneous connectivity. For epidemiology, this implies that network heterogeneity should not be studied in isolation, it is instead the heterogeneity of infection risk that determines the likelihood of outbreaks.

  3. Large epidemic thresholds emerge in heterogeneous networks of heterogeneous nodes.

    Science.gov (United States)

    Yang, Hui; Tang, Ming; Gross, Thilo

    2015-08-21

    One of the famous results of network science states that networks with heterogeneous connectivity are more susceptible to epidemic spreading than their more homogeneous counterparts. In particular, in networks of identical nodes it has been shown that network heterogeneity, i.e. a broad degree distribution, can lower the epidemic threshold at which epidemics can invade the system. Network heterogeneity can thus allow diseases with lower transmission probabilities to persist and spread. However, it has been pointed out that networks in which the properties of nodes are intrinsically heterogeneous can be very resilient to disease spreading. Heterogeneity in structure can enhance or diminish the resilience of networks with heterogeneous nodes, depending on the correlations between the topological and intrinsic properties. Here, we consider a plausible scenario where people have intrinsic differences in susceptibility and adapt their social network structure to the presence of the disease. We show that the resilience of networks with heterogeneous connectivity can surpass those of networks with homogeneous connectivity. For epidemiology, this implies that network heterogeneity should not be studied in isolation, it is instead the heterogeneity of infection risk that determines the likelihood of outbreaks.

  4. Modeling the cooperative and competitive contagions in online social networks

    Science.gov (United States)

    Zhuang, Yun-Bei; Chen, J. J.; Li, Zhi-hong

    2017-10-01

    The wide adoption of social media has increased the interaction among different pieces of information, and this interaction includes cooperation and competition for our finite attention. While previous research focus on fully competition, this paper extends the interaction to be both "cooperation" and "competition", by employing an IS1S2 R model. To explore how two different pieces of information interact with each other, the IS1S2 R model splits the agents into four parts-(Ignorant-Spreader I-Spreader II-Stifler), based on SIR epidemic spreading model. Using real data from Weibo.com, a social network site similar to Twitter, we find some parameters, like decaying rates, can both influence the cooperative diffusion process and the competitive process, while other parameters, like infectious rates only have influence on the competitive diffusion process. Besides, the parameters' effect are more significant in the competitive diffusion than in the cooperative diffusion.

  5. Heterogeneous gas core reactor

    International Nuclear Information System (INIS)

    Diaz, N.J.; Dugan, E.T.

    1983-01-01

    A heterogeneous gas core nuclear reactor is disclosed comprising a core barrel provided interiorly with an array of moderator-containing tubes and being otherwise filled with a fissile and/or fertile gaseous fuel medium. The fuel medium may be flowed through the chamber and through an external circuit in which heat is extracted. The moderator may be a fluid which is flowed through the tubes and through an external circuit in which heat is extracted. The moderator may be a solid which may be cooled by a fluid flowing within the tubes and through an external heat extraction circuit. The core barrel is surrounded by moderator/coolant material. Fissionable blanket material may be disposed inwardly or outwardly of the core barrel

  6. Heterogeneity in Waardenburg syndrome.

    Science.gov (United States)

    Hageman, M J; Delleman, J W

    1977-01-01

    Heterogeneity of Waardenburg syndrome is demonstrated in a review of 1,285 patients from the literature and 34 previously unreported patients in five families in the Netherlands. The syndrome seems to consist of two genetically distinct entities that can be differentiated clinically: type I, Waardenburg syndrome with dystopia canthorum; and type II, Waardenburg syndrome without dystopia canthorum. Both types have an autosomal dominant mode of inheritance. The incidence of bilateral deafness in the two types of the syndrome was found in one-fourth with type I and about half of the patients with type II. This difference has important consequences for genetic counseling. Images Fig. 7 Fig. 8 Fig. 9 PMID:331943

  7. Quantifying hidden individual heterogeneity

    DEFF Research Database (Denmark)

    Steiner, Ulrich; Lenart, Adam; Vaupel, James W.

    Aging is assumed to be driven by the accumulation of damage or some other aging factor which shapes demographic patterns, including the classical late age mortality plateaus. However to date, heterogeneity in these damage stages is not observed. Here, we estimate underlying stage distributions...... and stage dynamics, based on observed survival patterns of isoclonal bacteria. Our results reveal demographic dynamics being dominated by low damage stages and transmission of damage from mother to daughters is low. Still, our models are too simplistic and deterministic. Explaining the observed data...... requires more stochastic processes as our current models includes. We are only at the beginning of understanding the diverse mechanism behind aging and the shaping of senescence....

  8. Receiver Heterogeneity Helps

    DEFF Research Database (Denmark)

    Kovács, Erika R.; Pedersen, Morten Videbæk; Roetter, Daniel Enrique Lucani

    2014-01-01

    Heterogeneity amongst devices and desired service are commonly seen as a source of additional challenges for setting up an efficient multi-layer multicast service. In particular, devices requiring only the base layer can become a key bottleneck to the performance for other devices. This paper...... studies the case of a wireless multi-layer multicast setting and shows that the judicious use of network coding allows devices with different computational capabilities to trade-off processing complexity for an improved quality of service. As a consequence, individual devices can determine their required...... effort, while bringing significant advantages to the system as a whole. Network coding is used as a key element to reduce signaling in order to deliver the multicast service. More importantly, our proposed approach focuses on creating some structure in the transmitted stream by allowing inter-layer...

  9. Cooperating for assisting intelligently operators

    International Nuclear Information System (INIS)

    Brezillon, P.; Cases, E.; CEA Centre d'Etudes de la Vallee du Rhone, 30 - Marcoule

    1995-01-01

    We are in the process of an intelligent cooperative system in a nuclear plant application. The system must cooperate with an operator who accomplishes a task of supervision of a real-world process. We point out in the paper that a cooperation between a cooperative system and an operator has two modes: a waking state and a participating state. During the waking state, the system observes the operator's behavior and the consequences on the process. During the participation state, the cooperative system builds jointly with the user a solution to the problem. In our approach, the cooperation depends on the system capabilities to explain, to incrementally acquire knowledge and to make explicit the context of the cooperation. We develop these ideas in the framework of the design of the cooperative system in the nuclear plant. (authors). 22 refs., 1 fig

  10. Cooperation and cheating in microbes

    Science.gov (United States)

    Gore, Jeff

    2011-03-01

    Understanding the cooperative and competitive dynamics within and between species is a central challenge in evolutionary biology. Microbial model systems represent a unique opportunity to experimentally test fundamental theories regarding the evolution of cooperative behaviors. In this talk I will describe our experiments probing cooperation in microbes. In particular, I will compare the cooperative growth of yeast in sucrose and the cooperative inactivation of antibiotics by bacteria. In both cases we find that cheater strains---which don't contribute to the public welfare---are able to take advantage of the cooperator strains. However, this ability of cheaters to out-compete cooperators occurs only when cheaters are present at low frequency, thus leading to steady-state coexistence. These microbial experiments provide fresh insight into the evolutionary origin of cooperation.

  11. CTBTO international cooperation workshop

    International Nuclear Information System (INIS)

    1999-01-01

    The International Cooperation Workshop took place in Vienna, Austria, on 16 and 17 November 1998, with the participation of 104 policy/decision makers, Research and Development managers and diplomatic representatives from 58 States Signatories to the Comprehensive Nuclear-Test Ban Treaty (CTBT). The Workshop attempted to develop Treaty stipulations to: promote cooperation to facilitate and participate in the fullest possible exchange relating to technologies used in the verification of the Treaty; enable member states to strengthen national implementation of verification measures, and to benefit from the application of such technologies for peaceful purposes. The potential benefits arising from the CTBT monitoring, analysis and data communication systems are multifaceted, and as yet unknown. This Workshop provided the opportunity to examine some of these possibilities. An overview of the CTBT verification regime on the general aspects of the four monitoring technologies (seismic, hydro-acoustic, infrasound and radionuclides), including some of the elements that are the subject of international cooperation, were presented and discussed. Questions were raised on the potential benefits that can be derived by participating in the CTBT regime and broad-based discussions took place. Several concrete proposals on ways and means to facilitate and promote cooperation among States Signatories were suggested. The main points discussed by the participants can be summarized as follows: the purpose of the CTBT Organization is to assist member states to monitor Treaty compliance; the CTBT can be a highly effective technological tool which can generate wide-ranging data, which can be used for peaceful purposes; there are differences in the levels of technology development in the member states that is why peaceful applications should be supported by the Prep Com for the benefit of all member states, whether developed or developing, training being a key element to optimize the CTBT

  12. International cooperation for operating safety

    International Nuclear Information System (INIS)

    Dupuis, M.C.

    1989-03-01

    The international-cooperation organization in nuclear safety domain is discussed. The nuclear energy Direction Committee is helped by the Security Committee for Nuclear Power Plants in the cooperation between security organizations of member countries and in the safety and nuclear activity regulations. The importance of the cooperation between experts in human being and engine problems is underlined. The applied methods, exchange activities and activity analysis, and the cooperation of the Nuclear Energy Agency and international organizations is analysed [fr

  13. Cooperation in regional nuclear training

    International Nuclear Information System (INIS)

    Newstead, C.M.; Lee, D.S.; Spitalnik, J.

    1985-01-01

    This paper presents an overview of the nuclear training currently being undertaken in the countries of the co-authors, and considers the degree to which training problems are amenable to common solutions such as cooperative regional training programs. Different types of cooperation are discussed including the development of regional and international training centers, cooperative bilateral and multilateral training, and the proposed US International Nuclear Safety Training Academy. The paper provides suggestions of ways for enhancing regional cooperation

  14. Competing intelligent search agents in global optimization

    Energy Technology Data Exchange (ETDEWEB)

    Streltsov, S.; Vakili, P. [Boston Univ., MA (United States); Muchnik, I. [Rutgers Univ., Piscataway, NJ (United States)

    1996-12-31

    In this paper we present a new search methodology that we view as a development of intelligent agent approach to the analysis of complex system. The main idea is to consider search process as a competition mechanism between concurrent adaptive intelligent agents. Agents cooperate in achieving a common search goal and at the same time compete with each other for computational resources. We propose a statistical selection approach to resource allocation between agents that leads to simple and efficient on average index allocation policies. We use global optimization as the most general setting that encompasses many types of search problems, and show how proposed selection policies can be used to improve and combine various global optimization methods.

  15. Cooperative catalysis by silica-supported organic functional groups

    OpenAIRE

    Margelefsky, Eric L.; Zeidan, Ryan K.; Davis, Mark E.

    2008-01-01

    Hybrid inorganic–organic materials comprising organic functional groups tethered from silica surfaces are versatile, heterogeneous catalysts. Recent advances have led to the preparation of silica materials containing multiple, different functional groups that can show cooperative catalysis; that is, these functional groups can act together to provide catalytic activity and selectivity superior to what can be obtained from either monofunctional materials or homogeneous catalysts. This tutorial...

  16. Short versus long term benefits and the evolution of cooperation in the prisoner's dilemma game.

    Directory of Open Access Journals (Sweden)

    Markus Brede

    Full Text Available In this paper I investigate the evolution of cooperation in the prisoner's dilemma when individuals change their strategies subject to performance evaluation of their neighbours over variable time horizons. In the monochrome setting, in which all agents per default share the same performance evaluation rule, weighing past events strongly dramatically enhances the prevalence of cooperators. For co-evolutionary models, in which evaluation time horizons and strategies can co-evolve, I demonstrate that cooperation naturally associates with long-term evaluation of others while defection is typically paired with very short time horizons. Moreover, considering the continuous spectrum in between enhanced and discounted weights of past performance, cooperation is optimally supported when cooperators neither give enhanced weight to past nor more recent events, but simply average payoffs. Payoff averaging is also found to emerge as the dominant strategy for cooperators in co-evolutionary models, thus proposing a natural route to the evolution of cooperation in viscous populations.

  17. Cooperative Learning: Developments in Research

    Science.gov (United States)

    Gillies, Robyn M.

    2014-01-01

    Cooperative learning is widely recognized as a pedagogical practice that promotes socialization and learning among students from kindergarten through to college level and across different subject areas. Cooperative learning involves students working together to achieve common goals or complete group tasks. Interest in cooperative learning has…

  18. Conditional cooperation on three continents

    NARCIS (Netherlands)

    Kocher, M.G.; Cherry, T.; Kroll, S.; Netzer, R.; Sutter, M.

    2007-01-01

    We show in a public goods experiment on three continents that conditional cooperation is a universal behavioral regularity. Yet, the number of conditional cooperators and the extent of conditional cooperation are much higher in the U.S.A. than anywhere else.

  19. The governance of cooperative societies

    Directory of Open Access Journals (Sweden)

    Yaiza Juanes Sobradillo

    2005-12-01

    Full Text Available The present work aims to expose the appropriate legislation for cooperative societies to which Article 129 of the Spanish Constitution refers, deepen the analysis of the organs of management and control based on the Spanish and Basque Laws on Cooperatives and the Statute for the European Cooperative Societies.

  20. Cooperative Learning in Elementary Schools

    Science.gov (United States)

    Slavin, Robert E.

    2015-01-01

    Cooperative learning refers to instructional methods in which students work in small groups to help each other learn. Although cooperative learning methods are used for different age groups, they are particularly popular in elementary (primary) schools. This article discusses methods and theoretical perspectives on cooperative learning for the…

  1. Forestry cooperatives: past and present

    Science.gov (United States)

    Mark G. Rickenbach

    2006-01-01

    Forest landowner cooperatives are not a new phenomenon, but past efforts to create and sustain these businesses have been largely unsuccessful in the U.S. Before and just after World War II saw significant investment in cooperative development that failed to create durable business. The purpose of this chapter is to briefly describe the history of forestry cooperatives...

  2. Riot Control Agents

    Science.gov (United States)

    ... Submit What's this? Submit Button Facts About Riot Control Agents Interim document Recommend on Facebook Tweet Share Compartir What riot control agents are Riot control agents (sometimes referred to ...

  3. Interconnecting heterogeneous database management systems

    Science.gov (United States)

    Gligor, V. D.; Luckenbaugh, G. L.

    1984-01-01

    It is pointed out that there is still a great need for the development of improved communication between remote, heterogeneous database management systems (DBMS). Problems regarding the effective communication between distributed DBMSs are primarily related to significant differences between local data managers, local data models and representations, and local transaction managers. A system of interconnected DBMSs which exhibit such differences is called a network of distributed, heterogeneous DBMSs. In order to achieve effective interconnection of remote, heterogeneous DBMSs, the users must have uniform, integrated access to the different DBMs. The present investigation is mainly concerned with an analysis of the existing approaches to interconnecting heterogeneous DBMSs, taking into account four experimental DBMS projects.

  4. Age structure and cooperation in coevolutionary games on dynamic network

    Science.gov (United States)

    Qin, Zilong; Hu, Zhenhua; Zhou, Xiaoping; Yi, Jingzhang

    2015-04-01

    Our proposed model imitates the growth of a population and describes the age structure and the level of cooperation in games on dynamic network with continuous changes of structure and topology. The removal of nodes and links caused by age-dependent attack, together with the nodes addition standing for the newborns of population, badly ruins Matthew effect in this coevolutionary process. Though the network is generated by growth and preferential attachment, it degenerates into random network and it is no longer heterogeneous. When the removal of nodes and links is equal to the addition of nodes and links, the size of dynamic network is maintained in steady-state, so is the low level of cooperation. Severe structure variation, homogeneous topology and continuous invasion of new defection jointly make dynamic network unsuitable for the survival of cooperator even when the probability with which the newborn players initially adopt the strategy cooperation is high, while things change slightly when the connections of newborn players are restricted. Fortunately, moderate interactions in a generation trigger an optimal recovering process to encourage cooperation. The model developed in this paper outlines an explanation of the cohesion changes in the development process of an organization. Some suggestions for cooperative behavior improvement are given in the end.

  5. Relational Diversity Promotes Cooperation in Prisoner’s Dilemma Games

    Science.gov (United States)

    Xu, Bo; Wang, Jianwei; Deng, Ruipu; Li, Miao

    2014-01-01

    Relational diversity can be characterized by heterogeneous distributions of tie strengths in social networks and this diversity is present not only among humans, but throughout the animal world. We account for this observation by analyzing two network datasets from Facebook. We measure the strength of a tie by calculating the extent of overlap of friends between the two individuals. Based on the previous findings in human experiments, we argue that it is very unlikely that players will allocate their investments equally to their neighbors. There is a tendency that players prefer to donate more to their intimate friends. We find that if players preferentially allocate their investments to their good friends, cooperation will be promoted in PDG. We proved that the facilitation of the cooperative strategy relies mostly on the cooperative allies between best friends, resulting in the formation of cooperative clusters which are able to prevail against the defectors even when there is a large cost to cooperate. Moreover, we discover that the effect of relational diversity cannot be analyzed by adopting classical complex networks models, because neither of the artificial networks is able to produce networks with diverse distributions of tie strengths. It is of vital importance to introduce real social networks to study the influence of diverse relations especially when it comes to humans. This research proposes a brand new perspective to understand the influence of social relations on the emergence of cooperation in evolutionary prisoner’s dilemma games. PMID:25474354

  6. Cooperate or Free Ride?

    DEFF Research Database (Denmark)

    Hansen, Per H.

    2012-01-01

    of international cooperation. On the other hand, the evidence seems to confirm Kindleberger's hypothesis that small countries were free riding during the international financial crisis of 1931, and that therefore there is a need for some coordinating mechanism, or a hegemon, in such crises....... in the establishment of the BIS and free riders in the Austrian crisis, even though there were marked differences in their attitude to international cooperation. These results run counter to the views of those International Political Economy (IPE) theorists who argue that small states should be in favour......In this article, I discuss the role of the three Scandinavian central banks in the establishment of the Bank for International Settlements (BIS) in 1930, and in the international lender of last resort operation towards Austria in 1931. I argue that small central banks were reluctant supporters...

  7. Junctionless Cooper pair transistor

    Energy Technology Data Exchange (ETDEWEB)

    Arutyunov, K. Yu., E-mail: konstantin.yu.arutyunov@jyu.fi [National Research University Higher School of Economics , Moscow Institute of Electronics and Mathematics, 101000 Moscow (Russian Federation); P.L. Kapitza Institute for Physical Problems RAS , Moscow 119334 (Russian Federation); Lehtinen, J.S. [VTT Technical Research Centre of Finland Ltd., Centre for Metrology MIKES, P.O. Box 1000, FI-02044 VTT (Finland)

    2017-02-15

    Highlights: • Junctionless Cooper pair box. • Quantum phase slips. • Coulomb blockade and gate modulation of the Coulomb gap. - Abstract: Quantum phase slip (QPS) is the topological singularity of the complex order parameter of a quasi-one-dimensional superconductor: momentary zeroing of the modulus and simultaneous 'slip' of the phase by ±2π. The QPS event(s) are the dynamic equivalent of tunneling through a conventional Josephson junction containing static in space and time weak link(s). Here we demonstrate the operation of a superconducting single electron transistor (Cooper pair transistor) without any tunnel junctions. Instead a pair of thin superconducting titanium wires in QPS regime was used. The current–voltage characteristics demonstrate the clear Coulomb blockade with magnitude of the Coulomb gap modulated by the gate potential. The Coulomb blockade disappears above the critical temperature, and at low temperatures can be suppressed by strong magnetic field.

  8. Cooperative Learning i voksenundervisningen

    DEFF Research Database (Denmark)

    Wahlgren, Bjarne

    Nationalt Center for Kompetenceudvikling har evalueret undervisningsmetoden Cooperative Learning i voksenundervisningen og dokumenteret positive effekter på oplevelsen af samarbejde og på lærere og kursisters engagement - men har ikke kunnet påvise systematiske positive effekter af metoden på...... kursisters frafald, fravær og karakterer. Projektet har afprøvet og videreudviklet den pædagogiske metode Cooperative Learning (CL) i en dansk virkelighed og mere specifikt i forhold til VUC'ernes nye kursistgrupper med det overordnede mål at øge gennemførslen markant og målbart ved at anvende og udvikle en...

  9. International cooperative information systems

    International Nuclear Information System (INIS)

    1980-01-01

    Developing countries need mechanisms by which the information they generate themselves and development information from the rest of the world can be retrieved. The international cooperative information system is such a mechanism. Delegates to the Seminar on International Cooperative Information Systems were informed about various existing systems (INIS, AGRIS, INFOTERRA, TCDC/INRES, POPIN, DEVSIS, and INPADROC), some specialized information systems and services (CDS/ISIS and the Cassava Information Centre), and computer programs for information processing (INIS/AGRIS, CDS/ISIS, and MINISIS). The participants suggested some changes that should be made on both the national and the international levels to ensure that these systems meet the needs of developing countries more effectively. (LL)

  10. Cooperative method development

    DEFF Research Database (Denmark)

    Dittrich, Yvonne; Rönkkö, Kari; Eriksson, Jeanette

    2008-01-01

    The development of methods tools and process improvements is best to be based on the understanding of the development practice to be supported. Qualitative research has been proposed as a method for understanding the social and cooperative aspects of software development. However, qualitative...... research is not easily combined with the improvement orientation of an engineering discipline. During the last 6 years, we have applied an approach we call `cooperative method development', which combines qualitative social science fieldwork, with problem-oriented method, technique and process improvement....... The action research based approach focusing on shop floor software development practices allows an understanding of how contextual contingencies influence the deployment and applicability of methods, processes and techniques. This article summarizes the experiences and discusses the further development...

  11. Cooperation or Silent Rivalry?

    DEFF Research Database (Denmark)

    Zank, Wolfgang

    2010-01-01

    a gravitational pull which goes beyond economic problems. Furthermore, the EU has gradually built up a coherent policy on many fields. The EU has become the “reform anchor” and most important cooperation partner for Egypt. The progress towards increasing Egypt’s “Stake in the Internal Market” places cooperation......For decades the US has had a hegemonic position in the Middle East. A key country in this respect has been Egypt. However, in recent decades the EU has made itself increasingly felt in the region. Due to enlargements the EU came geographically much closer, and the Internal Market has generated...... to see the US and EU as rivals. Their roles are rather complementary. The article explores developments in a long-term perspective. Internal and structural developments have had a heavy impact, but at important junctions ideas and strategies for gaining political legitimacy were powerful factors too...

  12. Strategies of inducing cooperation

    International Nuclear Information System (INIS)

    Deutsch, M.

    1986-01-01

    The results of the four experiments described in this paper are very consistent, and they can be summarized as follows: (1) The ''nonpunitive'' strategy was most effective in eliciting cooperative behavior from the subjects and, overall, resulted in the highest joint outcomes as well as the highest outcomes for the accomplice. (2) The effectiveness of the turn-the-other-cheek strategy was very much influenced by the competitiveness of the situation; the more competitive the incentives of the subjects, the more massively they exploited the accomplice who employed this strategy. (3) The punitive deterrent strategy elicited more agressive and self-protective, as well as less cooperative, behavior from the subjects than did the other strategies

  13. Problems of technical cooperation

    International Nuclear Information System (INIS)

    Noramli, M.

    1987-01-01

    The main principles of the IAEA technical co-operation program, which intends to answer the requirements of the member states as regards technical assistance, are presented. IAEA offers its assistance in the supervision and financial support of the projects, which promise direct and quick profit to the member states. Projects related to the satisfaction of the main demands of humanity, industrial use, energy generation, radiation protection and other fields, which can promote the contribution of nuclear power generation to the course of peace, protection of health and thriving of states, are among them. 35 million dollars (USA) was allocated for the IAEA technical assistance and realization of the co-operation program in 1987

  14. Heterogeneous beliefs and routes to complex dynamics in asset pricing models with price contingent contracts

    NARCIS (Netherlands)

    Brock, W.A.; Hommes, C.H.

    2001-01-01

    This paper discusses dynamic evolutionary multi-agent systems, as introduced by Brock and Hommes (1997). In particular the heterogeneous agent dynamic asset pricing model of Brock and Hommes (1998) is extended by introducing derivative securities by means of price contingent contracts. Numerical

  15. Enresa International Cooperation

    International Nuclear Information System (INIS)

    Rodriguez Beceiro, A.

    1998-01-01

    The Empresa Nacional de Residuos Radiactivos, S.A. (ENRESA) was set up in 1984 with the mandate to undertake responsibility for radioactive waste management in Spain. From the very beginning, ENRESA was fully aware of the fact that international cooperation plays a very important role in the development of national programmes. Aspects such as the setting up of international databases, the development and validation of models or site characterization technique such enormous efforts and amounts of resources that they could hardly be undertaken individually. Furthermore, joint participation in research, development and demonstration projects reinforces the level of confidence, not only in the decision-making process but also in the technologies, techniques and practices used. ENRESA's participation in the international contexts is largely defined, on the one hand, by the needs arising from its technical programme, as reflected in the General Radioactive Waste Plan and in the Research and Development Plan, and on the other by the need to support spanish governmental institutions in their participation in inter-governmental institutions in their participation in inter-governmental forums. The formula for cooperation varies according to needs, this cooperation generally being accomplished by means of bilateral agreements with other institutions having similar competence or by participating in the programmes of inter-governmental organizations. In particular, ENRESA has reached cooperation agreements with most of the agencies with similar responsibilities in other countries and participates very actively in the programmes of the European Union, the Nuclear energy Agency (NEA/OECD) and the International Atomic Energy Agency (IAEA). (Author)

  16. Automated Cooperative Trajectories

    Science.gov (United States)

    Hanson, Curt; Pahle, Joseph; Brown, Nelson

    2015-01-01

    This presentation is an overview of the Automated Cooperative Trajectories project. An introduction to the phenomena of wake vortices is given, along with a summary of past research into the possibility of extracting energy from the wake by flying close parallel trajectories. Challenges and barriers to adoption of civilian automatic wake surfing technology are identified. A hardware-in-the-loop simulation is described that will support future research. Finally, a roadmap for future research and technology transition is proposed.

  17. Diversity and Cooperation

    OpenAIRE

    Bruner, Justin Pearce

    2014-01-01

    The present dissertation is an exploration of the effect of diversity on social contract formation and the evolution of cooperation. This work stems from the pioneering efforts of economist Arthur Robson, who first explored the role of costless pre-game communication in strategic interactions. When communication is permitted, individuals playing a game can condition their behavior on the signal received from their counterpart. For my purposes, I interpret these signals as racial markers or cu...

  18. Multiagent Cooperative Learning Strategies for Pursuit-Evasion Games

    Directory of Open Access Journals (Sweden)

    Jong Yih Kuo

    2015-01-01

    Full Text Available This study examines the pursuit-evasion problem for coordinating multiple robotic pursuers to locate and track a nonadversarial mobile evader in a dynamic environment. Two kinds of pursuit strategies are proposed, one for agents that cooperate with each other and the other for agents that operate independently. This work further employs the probabilistic theory to analyze the uncertain state information about the pursuers and the evaders and uses case-based reasoning to equip agents with memories and learning abilities. According to the concepts of assimilation and accommodation, both positive-angle and bevel-angle strategies are developed to assist agents in adapting to their environment effectively. The case study analysis uses the Recursive Porous Agent Simulation Toolkit (REPAST to implement a multiagent system and demonstrates superior performance of the proposed approaches to the pursuit-evasion game.

  19. Mutually cooperative epidemics on power-law networks

    Science.gov (United States)

    Cui, Peng-Bi; Colaiori, Francesca; Castellano, Claudio

    2017-08-01

    The spread of an infectious disease can, in some cases, promote the propagation of other pathogens favoring violent outbreaks, which cause a discontinuous transition to an endemic state. The topology of the contact network plays a crucial role in these cooperative dynamics. We consider a susceptible-infected-removed-type model with two mutually cooperative pathogens: An individual already infected with one disease has an increased probability of getting infected by the other. We present a heterogeneous mean-field theoretical approach to the coinfection dynamics on generic uncorrelated power-law degree-distributed networks and validate its results by means of numerical simulations. We show that, when the second moment of the degree distribution is finite, the epidemic transition is continuous for low cooperativity, while it is discontinuous when cooperativity is sufficiently high. For scale-free networks, i.e., topologies with diverging second moment, the transition is instead always continuous. In this way we clarify the effect of heterogeneity and system size on the nature of the transition, and we validate the physical interpretation about the origin of the discontinuity.

  20. Punishment does not promote cooperation under exploration dynamics when anti-social punishment is possible.

    Science.gov (United States)

    P Hauser, Oliver; A Nowak, Martin; G Rand, David

    2014-11-07

    It has been argued that punishment promotes the evolution of cooperation when mutation rates are high (i.e. when agents engage in 'exploration dynamics'). Mutations maintain a steady supply of agents that punish free-riders, and thus free-riders are at a disadvantage. Recent experiments, however, have demonstrated that free-riders sometimes also pay to punish cooperators. Inspired by these empirical results, theoretical work has explored evolutionary dynamics where mutants are rare, and found that punishment does not promote the evolution of cooperation when this 'anti-social punishment' is allowed. Here we extend previous theory by studying the effect of anti-social punishment on the evolution of cooperation across higher mutation rates, and by studying voluntary as well as compulsory Public Goods Games. We find that for intermediate and high mutation rates, adding punishment does not promote cooperation in either compulsory or voluntary public goods games if anti-social punishment is possible. This is because mutations generate agents that punish cooperators just as frequently as agents that punish defectors, and these two effects cancel each other out. These results raise questions about the effectiveness of punishment for promoting cooperation when mutations are common, and highlight how decisions about which strategies to include in the strategy set can have profound effects on the resulting dynamics. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Heterogeneity: multilingualism and democracy

    Directory of Open Access Journals (Sweden)

    Hans-Jürgen Krumm

    2004-01-01

    Full Text Available Linguistic diversity and multilingualism on the part of individuals are aprerequisite and a constitutive condition of enabling people to live togetherin a world of growing heterogeneity. Foreign language teaching plays animportant part in democratic education because it can be seen as a trainingin respecting otherness and developing an intercultural, non-ethnocentricperception and attitude. This is all the more important because of the neces-sity of integrating children from migrant families into school life.My article argues that language education policy has to take this per-spective into account, i.e., of establishing a planned diversification so thatpupils (and their parents will not feel satisfied with learning English only,but also become motivated to learn languages of their own neighbourhood,such as migrant and minority languages. However, in order to make use ofthe linguistic resources in the classroom, relating it to the democratic impetusof foreign language education, it is necessary to revise existing languagepolicies and to develop a multilingual perspective for all educational institutions.

  2. Heterogeneous burnable poisons:

    International Nuclear Information System (INIS)

    Leiva, Sergio; Agueda, Horacio; Russo, Diego

    1989-01-01

    The use of materials possessing high neutron absorption cross-section commonly known as 'burnable poisons' have its origin in BWR reactors with the purpose of improving the efficiency of the first fuel load. Later on, it was extended to PWR to compensate of initial reactivity without infringing the requirement of maintaining a negative moderator coefficient. The present tendency is to increase the use of solid burnable poisons to extend the fuel cycle life and discharge burnup. There are two concepts for the burnable poisons utilization: 1) heterogeneously distributions in the form of rods, plates, etc. and 2) homogeneous dispersions of burnable poisons in the fuel. The purpose of this work is to present the results of sinterability studies, performed on Al 2 O 3 -B 4 C and Al 2 O 3 -Gd 2 O 3 systems. Experiments were carried on pressing at room temperature mixtures of powders containing up to 5 wt % of B 4 C or Gd 2 O 3 in Al 2 O 3 and subsequently sintering at 1750 deg C in reducing atmosphere. Evaluation of density, porosity and microstructures were done and a comparison with previous experiences is shown. (Author) [es

  3. Heterogeneity of protein hormones

    Energy Technology Data Exchange (ETDEWEB)

    Rosselin, G; Bataille, D; Laburthe, M; Duran-Garcia, S [Institut National de la Sante et de la Recherche Medicale (INSERM), Hopital Saint-Antoine, 75 - Paris (France)

    1975-12-01

    Radioimmunoassay measures antigenic determinants of hormonal molecules in the plasmas and tissues. These estimations carried out after fractionation in biological fluids, have revealed several immunological forms of the same hormone. The main problem is in the relationship of the various immunoreactive forms to the same hormonal sequence. The similar immunoreactive forms of high molecular weight usually have low biological activity and suggest the presence of prohormone; the suggestion of prohormonal nature depends on the chronology of the incorporation of labelled leucine and enzymatic transformation of prohormone with low biological into active hormone. The forms with high molecular weight and similar immunological activity may be of another nature. Thus, it has been shown that the biosynthetic nature of a compound such as big big insulin in the rat is doubtful owing to the absence of specific incorporation of labelled leucine into the immunoprecipitate of this fraction. The significance of low molecular weight form is still little known. An example of these forms is supplied by the existence of an alpha sub-unit of gonadotrophin present in the plasma of menopausal women. The interest of analytical methods by radio-receptor, simulation of cyclase activity in the identification of biological activity of immunoreactive forms, is discussed in relation to immunological forms ofenteroglucagon. An unusual aspect of the evolutive and adaptative character of hormonal heterogeneity is given by the gastro-intestinal hormones.

  4. Parsing Heterogeneous Striatal Activity

    Directory of Open Access Journals (Sweden)

    Kae Nakamura

    2017-05-01

    Full Text Available The striatum is an input channel of the basal ganglia and is well known to be involved in reward-based decision making and learning. At the macroscopic level, the striatum has been postulated to contain parallel functional modules, each of which includes neurons that perform similar computations to support selection of appropriate actions for different task contexts. At the single-neuron level, however, recent studies in monkeys and rodents have revealed heterogeneity in neuronal activity even within restricted modules of the striatum. Looking for generality in the complex striatal activity patterns, here we briefly survey several types of striatal activity, focusing on their usefulness for mediating behaviors. In particular, we focus on two types of behavioral tasks: reward-based tasks that use salient sensory cues and manipulate outcomes associated with the cues; and perceptual decision tasks that manipulate the quality of noisy sensory cues and associate all correct decisions with the same outcome. Guided by previous insights on the modular organization and general selection-related functions of the basal ganglia, we relate striatal activity patterns on these tasks to two types of computations: implementation of selection and evaluation. We suggest that a parsing with the selection/evaluation categories encourages a focus on the functional commonalities revealed by studies with different animal models and behavioral tasks, instead of a focus on aspects of striatal activity that may be specific to a particular task setting. We then highlight several questions in the selection-evaluation framework for future explorations.

  5. Cooperating systems: Layered MAS

    Science.gov (United States)

    Rochowiak, Daniel

    1990-01-01

    Distributed intelligent systems can be distinguished by the models that they use. The model developed focuses on layered multiagent system conceived of as a bureaucracy in which a distributed data base serves as a central means of communication. The various generic bureaus of such a system is described and a basic vocabulary for such systems is presented. In presenting the bureaus and vocabularies, special attention is given to the sorts of reasonings that are appropriate. A bureaucratic model has a hierarchy of master system and work group that organizes E agents and B agents. The master system provides the administrative services and support facilities for the work groups.

  6. Decentralized Opportunistic Spectrum Resources Access Model and Algorithm toward Cooperative Ad-Hoc Networks.

    Directory of Open Access Journals (Sweden)

    Ming Liu

    Full Text Available Limited communication resources have gradually become a critical factor toward efficiency of decentralized large scale multi-agent coordination when both system scales up and tasks become more complex. In current researches, due to the agent's limited communication and observational capability, an agent in a decentralized setting can only choose a part of channels to access, but cannot perceive or share global information. Each agent's cooperative decision is based on the partial observation of the system state, and as such, uncertainty in the communication network is unavoidable. In this situation, it is a major challenge working out cooperative decision-making under uncertainty with only a partial observation of the environment. In this paper, we propose a decentralized approach that allows agents cooperatively search and independently choose channels. The key to our design is to build an up-to-date observation for each agent's view so that a local decision model is achievable in a large scale team coordination. We simplify the Dec-POMDP model problem, and each agent can jointly work out its communication policy in order to improve its local decision utilities for the choice of communication resources. Finally, we discuss an implicate resource competition game, and show that, there exists an approximate resources access tradeoff balance between agents. Based on this discovery, the tradeoff between real-time decision-making and the efficiency of cooperation using these channels can be well improved.

  7. Older partner selection promotes the prevalence of cooperation in evolutionary games.

    Science.gov (United States)

    Yang, Guoli; Huang, Jincai; Zhang, Weiming

    2014-10-21

    Evolutionary games typically come with the interplays between evolution of individual strategy and adaptation to network structure. How these dynamics in the co-evolution promote (or obstruct) the cooperation is regarded as an important topic in social, economic, and biological fields. Combining spatial selection with partner choice, the focus of this paper is to identify which neighbour should be selected as a role to imitate during the process of co-evolution. Age, an internal attribute and kind of local piece of information regarding the survivability of the agent, is a significant consideration for the selection strategy. The analysis and simulations presented, demonstrate that older partner selection for strategy imitation could foster the evolution of cooperation. The younger partner selection, however, may decrease the level of cooperation. Our model highlights the importance of agent׳s age on the promotion of cooperation in evolutionary games, both efficiently and effectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Quantifying spatial heterogeneity from images

    International Nuclear Information System (INIS)

    Pomerantz, Andrew E; Song Yiqiao

    2008-01-01

    Visualization techniques are extremely useful for characterizing natural materials with complex spatial structure. Although many powerful imaging modalities exist, simple display of the images often does not convey the underlying spatial structure. Instead, quantitative image analysis can extract the most important features of the imaged object in a manner that is easier to comprehend and to compare from sample to sample. This paper describes the formulation of the heterogeneity spectrum to show the extent of spatial heterogeneity as a function of length scale for all length scales to which a particular measurement is sensitive. This technique is especially relevant for describing materials that simultaneously present spatial heterogeneity at multiple length scales. In this paper, the heterogeneity spectrum is applied for the first time to images from optical microscopy. The spectrum is measured for thin section images of complex carbonate rock cores showing heterogeneity at several length scales in the range 10-10 000 μm.

  9. Agent-Based Data Integration Framework

    Directory of Open Access Journals (Sweden)

    Łukasz Faber

    2014-01-01

    Full Text Available Combining data from diverse, heterogeneous sources while facilitating a unified access to it is an important (albeit difficult task. There are various possibilities of performing it. In this publication, we propose and describe an agent-based framework dedicated to acquiring and processing distributed, heterogeneous data collected from diverse sources (e.g., the Internet, external software, relational, and document databases. Using this multi-agent-based approach in the aspects of the general architecture (the organization and management of the framework, we create a proof-of-concept implementation. The approach is presented using a sample scenario in which the system is used to search for personal and professional profiles of scientists.

  10. Genetic architecture promotes the evolution and maintenance of cooperation.

    Directory of Open Access Journals (Sweden)

    Antoine Frénoy

    Full Text Available When cooperation has a direct cost and an indirect benefit, a selfish behavior is more likely to be selected for than an altruistic one. Kin and group selection do provide evolutionary explanations for the stability of cooperation in nature, but we still lack the full understanding of the genomic mechanisms that can prevent cheater invasion. In our study we used Aevol, an agent-based, in silico genomic platform to evolve populations of digital organisms that compete, reproduce, and cooperate by secreting a public good for tens of thousands of generations. We found that cooperating individuals may share a phenotype, defined as the amount of public good produced, but have very different abilities to resist cheater invasion. To understand the underlying genetic differences between cooperator types, we performed bio-inspired genomics analyses of our digital organisms by recording and comparing the locations of metabolic and secretion genes, as well as the relevant promoters and terminators. Association between metabolic and secretion genes (promoter sharing, overlap via frame shift or sense-antisense encoding was characteristic for populations with robust cooperation and was more likely to evolve when secretion was costly. In mutational analysis experiments, we demonstrated the potential evolutionary consequences of the genetic association by performing a large number of mutations and measuring their phenotypic and fitness effects. The non-cooperating mutants arising from the individuals with genetic association were more likely to have metabolic deleterious mutations that eventually lead to selection eliminating such mutants from the population due to the accompanying fitness decrease. Effectively, cooperation evolved to be protected and robust to mutations through entangled genetic architecture. Our results confirm the importance of second-order selection on evolutionary outcomes, uncover an important genetic mechanism for the evolution and

  11. Reasoning about emotional agents

    OpenAIRE

    Meyer, J.-J.

    2004-01-01

    In this paper we discuss the role of emotions in artificial agent design, and the use of logic in reasoning about the emotional or affective states an agent can reside in. We do so by extending the KARO framework for reasoning about rational agents appropriately. In particular we formalize in this framework how emotions are related to the action monitoring capabilities of an agent.

  12. Heterogeneity of reward mechanisms.

    Science.gov (United States)

    Lajtha, A; Sershen, H

    2010-06-01

    The finding that many drugs that have abuse potential and other natural stimuli such as food or sexual activity cause similar chemical changes in the brain, an increase in extracellular dopamine (DA) in the shell of the nucleus accumbens (NAccS), indicated some time ago that the reward mechanism is at least very similar for all stimuli and that the mechanism is relatively simple. The presently available information shows that the mechanisms involved are more complex and have multiple elements. Multiple brain regions, multiple receptors, multiple distinct neurons, multiple transmitters, multiple transporters, circuits, peptides, proteins, metabolism of transmitters, and phosphorylation, all participate in reward mechanisms. The system is variable, is changed during development, is sex-dependent, and is influenced by genetic differences. Not all of the elements participate in the reward of all stimuli. Different set of mechanisms are involved in the reward of different drugs of abuse, yet different mechanisms in the reward of natural stimuli such as food or sexual activity; thus there are different systems that distinguish different stimuli. Separate functions of the reward system such as anticipation, evaluation, consummation and identification; all contain function-specific elements. The level of the stimulus also influences the participation of the elements of the reward system, there are possible reactions to even below threshold stimuli, and excessive stimuli can change reward to aversion involving parts of the system. Learning and memory of past reward is an important integral element of reward and addictive behavior. Many of the reward elements are altered by repeated or chronic stimuli, and chronic exposure to one drug is likely to alter the response to another stimulus. To evaluate and identify the reward stimulus thus requires heterogeneity of the reward components in the brain.

  13. Heterogeneous ice nucleation

    Energy Technology Data Exchange (ETDEWEB)

    Bogdan, A. [Helsinki Univ. (Finland). Dept. of Physics

    1994-12-31

    The classical theory of heterogenous ice nucleation is reviewed in detail. The modelling of ice nucleation in the adsorbed water films on natural particles by analogous ice nucleation in adsorbed water films on the walls of porous media is discussed. Ice nucleation in adsorbed films of purewater and the HNO{sub 3}/H{sub 2}0 binary system on the surface of porous aerosol (SiO{sub 2}) was investigated using the method of NMR spectroscopy. The median freezing temperature and freezing temperature region were shown to be highly sensitive both to the average thickness of the adsorbed films and to the amount of adsorbed nitric acid. The character of the ice phase formation tends to approach that of bulk liquid with increasing adsorbed film thickness. Under the given conditions the thickness of the adsorbed films decreases with an increasing amount of adsorbed nitric acid molecules The molar concentration of nitric acid in the adsorbed films is very small (of the order of 10{sup -}3 10{sup -}2 (M/l)). Nitric acid molecules tend to adsorb on the surface of aerosol to a greater extent than in subsequent layers. The concentration is greatest in layers situated close to the surface and sharply decreases with the distance from the surface. The difference between the median freezing temperatures for adsorbed pure water and for the binary system was found to be about 9 K for films of equal thickness. This is about 150 times greater than the difference between the median freezing temperatures of bulk pure water and a solution with the same concentration of nitric acid. (orig.)

  14. Heterogeneous dissipative composite structures

    Science.gov (United States)

    Ryabov, Victor; Yartsev, Boris; Parshina, Ludmila

    2018-05-01

    The paper suggests mathematical models of decaying vibrations in layered anisotropic plates and orthotropic rods based on Hamilton variation principle, first-order shear deformation laminated plate theory (FSDT), as well as on the viscous-elastic correspondence principle of the linear viscoelasticity theory. In the description of the physical relationships between the materials of the layers forming stiff polymeric composites, the effect of vibration frequency and ambient temperature is assumed as negligible, whereas for the viscous-elastic polymer layer, temperature-frequency relationship of elastic dissipation and stiffness properties is considered by means of the experimentally determined generalized curves. Mitigation of Hamilton functional makes it possible to describe decaying vibration of anisotropic structures by an algebraic problem of complex eigenvalues. The system of algebraic equation is generated through Ritz method using Legendre polynomials as coordinate functions. First, real solutions are found. To find complex natural frequencies of the system, the obtained real natural frequencies are taken as input values, and then, by means of the 3rd order iteration method, complex natural frequencies are calculated. The paper provides convergence estimates for the numerical procedures. Reliability of the obtained results is confirmed by a good correlation between analytical and experimental values of natural frequencies and loss factors in the lower vibration tones for the two series of unsupported orthotropic rods formed by stiff GRP and CRP layers and a viscoelastic polymer layer. Analysis of the numerical test data has shown the dissipation & stiffness properties of heterogeneous composite plates and rods to considerably depend on relative thickness of the viscoelastic polymer layer, orientation of stiff composite layers, vibration frequency and ambient temperature.

  15. AFRA: Supporting regional cooperation

    International Nuclear Information System (INIS)

    2016-01-01

    The African Regional Cooperative Agreement for Research, Development and Training Related to Nuclear Science and Technology (AFRA) provides a framework for African Member States to intensify their collaboration through programmes and projects focused on the specific shared needs of its members. It is a formal intergovernmental agreement which entered into force in 1990. In the context of AFRA, Regional Designated Centres for training and education in radiation protection (RDCs) are established African institutions able to provide services, such as training of highly qualified specialists or instructors needed at the national level and also to facilitate exchange of experience and information through networks of services operating in the field

  16. Cooperative Robot Localization Using Event-Triggered Estimation

    Science.gov (United States)

    Iglesias Echevarria, David I.

    It is known that multiple robot systems that need to cooperate to perform certain activities or tasks incur in high energy costs that hinder their autonomous functioning and limit the benefits provided to humans by these kinds of platforms. This work presents a communications-based method for cooperative robot localization. Implementing concepts from event-triggered estimation, used with success in the field of wireless sensor networks but rarely to do robot localization, agents are able to only send measurements to their neighbors when the expected novelty in this information is high. Since all agents know the condition that triggers a measurement to be sent or not, the lack of a measurement is therefore informative and fused into state estimates. In the case agents do not receive either direct nor indirect measurements of all others, the agents employ a covariance intersection fusion rule in order to keep the local covariance error metric bounded. A comprehensive analysis of the proposed algorithm and its estimation performance in a variety of scenarios is performed, and the algorithm is compared to similar cooperative localization approaches. Extensive simulations are performed that illustrate the effectiveness of this method.

  17. Costly punishment and cooperation in the evolutionary snowdrift game

    Science.gov (United States)

    Xu, C.; Ji, M.; Yap, Yee Jiun; Zheng, Da-Fang; Hui, P. M.

    2011-05-01

    The role of punishments in promoting cooperation is an important issue. We incorporate costly punishments into the snowdrift game (SG) by introducing a third punishing (P) character, and study the effects. The punishers, who carry basically a cooperative (C) character, are willing to pay a cost α so as to punish a non-cooperative (D) opponent by β. Depending on the initial fractions of the characters, α, β, and the cost-to-benefit ratio r in the SG, the three-character system evolves into a steady state consisting either only of C and P characters or only of C and D characters, in a well-mixed population. The former situation represents an enhancement in cooperation relative to the SG, while the latter is similar to the SG. The dynamics in approaching these different steady states are found to be different. Analytically, the key features in the dynamics and the steady states observed in simulations are captured by a set of differential equations. The sensitivity to the initial distribution of characters is studied by depicting the flow in a phase portrait and analyzing the nature of fixed points. The analysis also shows the role of P-character agents in preventing a system from invasion by D-character agents. Starting from a population consisting only of C and P agents, a D-character agent intended to invade the system cannot survive when the initial fraction of P agents is greater than r/β. Our model, defined intentionally as a simulation algorithm, can be readily generalized to incorporate many interesting effects, such as those in a networked population.

  18. Imitating winner or sympathizing loser? Quadratic effects on cooperative behavior in prisoners' dilemma games

    Science.gov (United States)

    Lu, Peng

    2015-10-01

    Cooperation is vital in human societies and therefore is widely investigated in the evolutionary game theory. Varieties of mechanisms have been proposed to overcome temptation and promote cooperation. Existing studies usually believe that agents are rational, but irrationalism such as emotions and feelings matters as well. Winner and loser are defined by their payoffs. In addition to admiring and imitating winners, the mechanism of sympathizing and imitating losers is introduced into the model as an alternative action rule, and each one plays the prisoners' dilemma game with eight neighbors under the influence of both irrationalism and rationalism. Rationalism refers to imitating winner to get highest payoff, and irrationalism means that people sympathize and adopt the actions of losers. As it is widely recognized that temptation reduces cooperation, this study focuses on the effect of sympathy on cooperation within a certain group or society. If it overcomes temptation that leads to defection, sympathy will be a powerful mechanism to promote cooperative behavior. Simulation results indicate that sympathy and temptation shares similar quadratic relationships with cooperation. Both sympathy and temptation undermine cooperation below their thresholds, and they both promote cooperation above their thresholds. Temptation not only reduces cooperation but also promote it as temptation goes beyond the threshold. Although sympathy is a good merit or human nature that is beneficial to society, a crisis or collapse of cooperation is inevitable when the sympathy propensity is relatively smaller. After cooperation reaches a minimal bottom, it then rises increasingly and dramatically, which brings a much brighter future of the society.

  19. When does inferring reputation probability countervail temptation in cooperative behaviors for the prisoners’ dilemma game?

    International Nuclear Information System (INIS)

    Dai, Yu; Lu, Peng

    2015-01-01

    In evolutionary games, the temptation mechanism reduces cooperation percentage while the reputation mechanism promotes it. Inferring reputation theory proposes that agent's imitating neighbors with the highest reputation takes place with a probability. Although reputation promotes cooperation, when and how it enhances cooperation is still a question. This paper investigates the condition where the inferring reputation probability promotes cooperation. Hence, the effects of reputation and temptation on cooperation are explored under the spatial prisoners’ dilemma game, utilizing the methods of simulation and statistical analysis. Results show that temptation reduces cooperation unconditionally while reputation promotes it conditionally, i.e. reputation countervails temptation conditionally. When the inferring reputation probability is less than 0.5, reputation promotes cooperation substantially and thus countervails temptation. However, when the inferring reputation probability is larger than 0.5, its contribution to cooperation is relatively weak and cannot prevent temptation from undermining cooperation. Reputation even decreases cooperation together with temptation when the probability is higher than 0.8. It should be noticed that inferring reputation does not always succeed to countervail temptation and there is a specific interval for it to promote cooperation

  20. Generating Self-Reliant Teams of Autonomous Cooperating Robots: Desired design Characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Parker, L.E.

    1999-05-01

    The difficulties in designing a cooperative team are significant. Several of the key questions that must be resolved when designing a cooperative control architecture include: How do we formulate, describe, decompose, and allocate problems among a group of intelligent agents? How do we enable agents to communicate and interact? How do we ensure that agents act coherently in their actions? How do we allow agents to recognize and reconcile conflicts? However, in addition to these key issues, the software architecture must be designed to enable multi-robot teams to be robust, reliable, and flexible. Without these capabilities, the resulting robot team will not be able to successfully deal with the dynamic and uncertain nature of the real world. In this extended abstract, we first describe these desired capabilities. We then briefly describe the ALLIANCE software architecture that we have previously developed for multi-robot cooperation. We then briefly analyze the ALLIANCE architecture in terms of the desired design qualities identified.

  1. Financial problems and cooperation

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, J.

    1994-12-31

    For a Bank, an usual way to attract new clients is by offering better interest rates depending on the amount of money that the client deposits in an account: {open_quotes}The more money you have the higher interest rate you get{close_quotes}. For a company is also a common practice to offer their clients discounts connected with the number of units of the product they order: {open_quotes}The more you order, the lower price per unit you pay{close_quotes}. From these situations arises the possibility to take profit if the clients cooperate and join their money or their orders. Hence, we define a new class of cooperative games called Financial Games. We study basic properties and necessary conditions for a game to belong to this class of games and we define the concept of duality for Financial games. The core is always non-empty and, moreover, Financial games are always totally balanced. We look at some special amputations lying in the Core and we study the reduced game on the j{sup th} player at {rvec x} where x{sub j} = b{sub j} = v(N) {minus} v(N {minus} j).

  2. Precompetitive cooperative research

    International Nuclear Information System (INIS)

    Holton, W.C.

    1991-01-01

    This paper reports that in the current worldwide technology environment, it is essential for the U.S. microelectronics industry, and especially for the integrated circuit portion of that industry, that precompetitive cooperative research alliances be formed and funded at a level that enables them to be effective in rapidly advancing technology. It is important to realize that technology advances with or without our direct participation. If we do not aggressively participate we are quickly left behind. Increasing complexity and miniaturization have been the themes in semiconductor technology. Many are aware that what began in the early 60's with a few masking steps and minimum dimensions measured in mils, has now evolved to a level of sophistication requiring a 100 MIP workstation for IC design and the investment of nearly $400 million dollars in fab cost to produce today's microchips. The leading nations of the world have come to realize that their future well- being is closely tied to their ability to compete in this hi- tech environment. Industry coalitions have been formed to exploit the early ramifications of emerging technologies. Improvements in overseas manufacturing have been made and continue unabated with new products, new processes, and new services being introduced at an increasing rate. Many foreign governments are now actively involved in formulating and conducting industrial and technology policies to aid their hi-tech industry. To meet these challenges, U.S. firms, with U.S. government cooperation, must respond

  3. Unifying perspectives on cooperation under social viscosity. Comment on "Universal scaling for the dilemma strength in evolutionary games" by Z. Wang et al.

    Science.gov (United States)

    Bauch, Chris T.

    2015-09-01

    How cooperation evolved in populations of self-interested agents puzzled Charles Darwin, who portrayed the paradox in The Descent of Man as such: "He who was ready to sacrifice his life, as many a savage has been, rather than betray his comrades, would often leave no offspring to inherit his noble nature" [1]. Darwin invoked group selection to explain cooperation: if groups of cooperating individuals could work together to outcompete groups of selfish individuals, cooperation could thrive. Fundamentally, this mechanism works by allowing cooperators to interact preferentially with one another: cooperators tend to interact with other co-operators whereas selfish "defectors" tend to interact with other defectors. Since cooperators cooperate and defectors defect, groups of cooperators should do better, on average.

  4. Teleworking through cooperation

    Directory of Open Access Journals (Sweden)

    Dario Minervini

    2006-07-01

    scheme is strictly connected to new technologies and cooperation is an important dimension of teleworking. In our study, cooperation is found performed both in social relations between employers and employees and in institutionalized relations between managers and unions. Although the two forms of cooperation, here called “social trustee cooperation” and “institutional cooperation”, are often thought as prerequisites of “best practices” of new working arrangements, our case studies demonstrate that cooperation has not always arisen that make possible to implement practices of teleworking. By focusing on cooperative relations, the results of different case studies in industry and in the service sector are discussed, thus intending to contribute to the development of sociological debate on telework.

  5. Diagnosis and heterogeneity of MS in MRI

    International Nuclear Information System (INIS)

    Holst, B.; Fiehler, J.; Schippling, S.

    2008-01-01

    An efficient therapy of MS requires a quick and reliable diagnosis of the disease. MRI is the most leading paraclinical examination for MS diagnosis. Even though there is no pathognomic finding in MRI, there are MS characteristics with respect to morphology and localization. To exclude other neurological disorders and distinguish between different characteristics within MS, the use of contrast agent is advantageous. Postulated MRI criteria have been increasingly adjusted to the clinical routine and have become clearer, more sensitive, and more specific. Different imaging criteria will be introduced. In addition to the McDonald criteria of 2001 and 2005, new criteria will be presented in which the use of contrast agent is replaced by a second MRI and the dissemination in time and space is simplified. Different pathomechanisms which help to separate MS patients into subgroups are postulated. The diverse pathomechanisms also enable the development of new pharmaceuticals to manipulate the immunologic course in different stages. For varying therapy approaches, it is increasingly important to differentiate the heterogeneous appearance forms into subtypes. The two visible main components of the disorder in MRI are inflammation and neurodegeneration and are responsible for different clinical courses. Both are interdependent and independent of each other. We introduce a stratification which uses both components as a function of their different outcomes to compose subgroups. The previous challenge with respect to MRI was to support the diagnosis of MS via MRI criteria. A future problem will be the heterogeneity and classification of subgroups. This article gives an overview of both problems. (orig.)

  6. Consensus of Heterogeneous Multiagent Systems with Arbitrarily Bounded Communication Delay

    Directory of Open Access Journals (Sweden)

    Xue Li

    2017-01-01

    Full Text Available This paper focuses on the consensus problem of high-order heterogeneous multiagent systems with arbitrarily bounded communication delays. Through the method of nonnegative matrices, we get a sufficient consensus condition for the systems with dynamically changing topology. The results of this paper show, even when there are arbitrarily bounded communication delays in the systems, all agents can reach a consensus no matter whether there are spanning trees for the corresponding communication graphs at any time.

  7. Imaging metabolic heterogeneity in cancer.

    Science.gov (United States)

    Sengupta, Debanti; Pratx, Guillem

    2016-01-06

    As our knowledge of cancer metabolism has increased, it has become apparent that cancer metabolic processes are extremely heterogeneous. The reasons behind this heterogeneity include genetic diversity, the existence of multiple and redundant metabolic pathways, altered microenvironmental conditions, and so on. As a result, methods in the clinic and beyond have been developed in order to image and study tumor metabolism in the in vivo and in vitro regimes. Both regimes provide unique advantages and challenges, and may be used to provide a picture of tumor metabolic heterogeneity that is spatially and temporally comprehensive. Taken together, these methods may hold the key to appropriate cancer diagnoses and treatments in the future.

  8. The value of international cooperation for abating global climate change

    International Nuclear Information System (INIS)

    Hammitt, James K.; Adams, John L.

    1996-01-01

    Because abatement of global climate change is a public good, independent national actions may not produce the efficient quantity. Using a numerical integrated-assessment model, abatement costs and damages induced by climate change are compared at the cooperative and noncooperative solutions to a set of two-party dynamic games between the industrialized and developing countries. Games with perfect and imperfect information about climate and economic factors are considered. Across 144 games with perfect information, incorporating different values of climate and economic parameters, the noncooperative solution usually yields global benefits comparable to those of the cooperative solution. In about one-fifth of these games, however, a second noncooperative solution exists which yields none of the benefits of the cooperative solution. In a game with imperfect information, where the state of nature is uncertain in the first but known in the second of two periods, the expected benefits of the noncooperative solution are 98% of the expected benefits of the cooperative solution. In contrast to single-agent studies which show little cost to delaying abatement, the benefits of cooperation are usually lost if cooperation is delayed 20 years

  9. Forgetting constrains the emergence of cooperative decision strategies

    Directory of Open Access Journals (Sweden)

    Jeffrey R. Stevens

    2011-01-01

    Full Text Available Theoretical studies of cooperative behavior have focused on decision strategies that depend on a partner's last choices. The findings from this work assume that players accurately remember past actions. The kind of memory that these strategies employ, however, does not reflect what we know about memory. Here, we show that human memory may not meet the requirements needed to use these strategies. When asked to recall the previous behavior of simulated partners in a cooperative memory task, participants performed poorly, making errors in 10-24% of the trials. Participants made more errors when required to track more partners. We conducted agent-based simulations to evaluate how well cooperative strategies cope with error. These simulations suggest that, even with few errors, cooperation could not be maintained at the error rates demonstrated by our participants. Our results indicate that the strategies typically used in the study of cooperation likely do not reflect the underlying cognitive capacities used by humans and other animals in social interactions. By including unrealistic assumptions about cognition, theoretical models may have overestimated the robustness of the existing cooperative strategies. To remedy this, future models should incorporate what we know about cognition.

  10. Political Ideology, Trust, and Cooperation

    Science.gov (United States)

    Balliet, Daniel; Tybur, Joshua M.; Wu, Junhui; Antonellis, Christian; Van Lange, Paul A. M.

    2016-01-01

    Theories suggest that political ideology relates to cooperation, with conservatives being more likely to pursue selfish outcomes, and liberals more likely to pursue egalitarian outcomes. In study 1, we examine how political ideology and political party affiliation (Republican vs. Democrat) predict cooperation with a partner who self-identifies as Republican or Democrat in two samples before (n = 362) and after (n = 366) the 2012 US presidential election. Liberals show slightly more concern for their partners’ outcomes compared to conservatives (study 1), and in study 2 this relation is supported by a meta-analysis (r = .15). However, in study 1, political ideology did not relate to cooperation in general. Both Republicans and Democrats extend more cooperation to their in-group relative to the out-group, and this is explained by expectations of cooperation from in-group versus out-group members. We discuss the relation between political ideology and cooperation within and between groups. PMID:29593363

  11. The Professionalization of Intelligence Cooperation

    DEFF Research Database (Denmark)

    Svendsen, Adam David Morgan

    "Providing an in-depth insight into the subject of intelligence cooperation (officially known as liason), this book explores the complexities of this process. Towards facilitating a general understanding of the professionalization of intelligence cooperation, Svendsen's analysis includes risk...... management and encourages the realisation of greater resilience. Svendsen discusses the controversial, mixed and uneven characterisations of the process of the professionalization of intelligence cooperation and argues for a degree of 'fashioning method out of mayhem' through greater operational...

  12. ITDB Cooperation With International Organizations

    International Nuclear Information System (INIS)

    2010-01-01

    IAEA illicit trafficking database cooperates with many international organizations. Among these organizations are Interpol, Universal Postal Union,and World Customs Organization. Other organizations are Organization for Security and Cooperation in Europe, UN Economic Commission for Europe, UN-Department of Disarmament Affairs and UN office for Drug and Crime. The cooperation with Interpol involves consultations on issues of training and technical assistance and other matters of common interest.

  13. Coevolution of Cooperation and Layer Selection Strategy in Multiplex Networks

    Directory of Open Access Journals (Sweden)

    Katsuki Hayashi

    2016-11-01

    Full Text Available Recently, the emergent dynamics in multiplex networks, composed of layers of multiple networks, has been discussed extensively in network sciences. However, little is still known about whether and how the evolution of strategy for selecting a layer to participate in can contribute to the emergence of cooperative behaviors in multiplex networks of social interactions. To investigate these issues, we constructed a coevolutionary model of cooperation and layer selection strategies in which each an individual selects one layer from multiple layers of social networks and plays the Prisoner’s Dilemma with neighbors in the selected layer. We found that the proportion of cooperative strategies increased with increasing the number of layers regardless of the degree of dilemma, and this increase occurred due to a cyclic coevolution process of game strategies and layer selection strategies. We also showed that the heterogeneity of links among layers is a key factor for multiplex networks to facilitate the evolution of cooperation, and such positive effects on cooperation were observed regardless of the difference in the stochastic properties of network topologies.

  14. Chemical warfare agents.

    Science.gov (United States)

    Kuca, Kamil; Pohanka, Miroslav

    2010-01-01

    Chemical warfare agents are compounds of different chemical structures. Simple molecules such as chlorine as well as complex structures such as ricin belong to this group. Nerve agents, vesicants, incapacitating agents, blood agents, lung-damaging agents, riot-control agents and several toxins are among chemical warfare agents. Although the use of these compounds is strictly prohibited, the possible misuse by terrorist groups is a reality nowadays. Owing to this fact, knowledge of the basic properties of these substances is of a high importance. This chapter briefly introduces the separate groups of chemical warfare agents together with their members and the potential therapy that should be applied in case someone is intoxicated by these agents.

  15. Social heuristics shape intuitive cooperation.

    Science.gov (United States)

    Rand, David G; Peysakhovich, Alexander; Kraft-Todd, Gordon T; Newman, George E; Wurzbacher, Owen; Nowak, Martin A; Greene, Joshua D

    2014-04-22

    Cooperation is central to human societies. Yet relatively little is known about the cognitive underpinnings of cooperative decision making. Does cooperation require deliberate self-restraint? Or is spontaneous prosociality reined in by calculating self-interest? Here we present a theory of why (and for whom) intuition favors cooperation: cooperation is typically advantageous in everyday life, leading to the formation of generalized cooperative intuitions. Deliberation, by contrast, adjusts behaviour towards the optimum for a given situation. Thus, in one-shot anonymous interactions where selfishness is optimal, intuitive responses tend to be more cooperative than deliberative responses. We test this 'social heuristics hypothesis' by aggregating across every cooperation experiment using time pressure that we conducted over a 2-year period (15 studies and 6,910 decisions), as well as performing a novel time pressure experiment. Doing so demonstrates a positive average effect of time pressure on cooperation. We also find substantial variation in this effect, and show that this variation is partly explained by previous experience with one-shot lab experiments.

  16. Regional cooperation in transportation planning.

    Science.gov (United States)

    2012-02-01

    As Floridas urbanized areas grow and merge, : neighboring jurisdictions experience interrelated : problems and opportunities, and regional : cooperation becomes an imperative. In the : transportation sector, Floridas metropolitan : planning org...

  17. Is cooperation viable in mobile organisms? Simple Walk Away rule favors the evolution of cooperation in groups

    Science.gov (United States)

    Aktipis, C. Athena

    2011-01-01

    The evolution of cooperation through partner choice mechanisms is often thought to involve relatively complex cognitive abilities. Using agent-based simulations I model a simple partner choice rule, the ‘Walk Away’ rule, where individuals stay in groups that provide higher returns (by virtue of having more cooperators), and ‘Walk Away’ from groups providing low returns. Implementing this conditional movement rule in a public goods game leads to a number of interesting findings: 1) cooperators have a selective advantage when thresholds are high, corresponding to low tolerance for defectors, 2) high thresholds lead to high initial rates of movement and low final rates of movement (after selection), and 3) as cooperation is selected, the population undergoes a spatial transition from high migration (and a many small and ephemeral groups) to low migration (and large and stable groups). These results suggest that the very simple ‘Walk Away’ rule of leaving uncooperative groups can favor the evolution of cooperation, and that cooperation can evolve in populations in which individuals are able to move in response to local social conditions. A diverse array of organisms are able to leave degraded physical or social environments. The ubiquitous nature of conditional movement suggests that ‘Walk Away’ dynamics may play an important role in the evolution of social behavior in both cognitively complex and cognitively simple organisms. PMID:21666771

  18. Viscous fingering with permeability heterogeneity

    International Nuclear Information System (INIS)

    Tan, C.; Homsy, G.M.

    1992-01-01

    Viscous fingering in miscible displacements in the presence of permeability heterogeneities is studied using two-dimensional simulations. The heterogeneities are modeled as stationary random functions of space with finite correlation scale. Both the variance and scale of the heterogeneities are varied over modest ranges. It is found that the fingered zone grows linearly in time in a fashion analogous to that found in homogeneous media by Tan and Homsy [Phys. Fluids 31, 1330 (1988)], indicating a close coupling between viscous fingering on the one hand and flow through preferentially more permeable paths on the other. The growth rate of the mixing zone increases monotonically with the variance of the heterogeneity, as expected, but shows a maximum as the correlation scale is varied. The latter is explained as a ''resonance'' between the natural scale of fingers in homogeneous media and the correlation scale

  19. Tumor Heterogeneity and Drug Resistance

    International Nuclear Information System (INIS)

    Kucerova, L.; Skolekova, S.; Kozovska, Z.

    2015-01-01

    New generation of sequencing methodologies revealed unexpected complexity and genomic alterations linked with the tumor subtypes. This diversity exists across the tumor types, histologic tumor subtypes and subsets of the tumor cells within the same tumor. This phenomenon is termed tumor heterogeneity. Regardless of its origin and mechanisms of development it has a major impact in the clinical setting. Genetic, phenotypic and expression pattern diversity of tumors plays critical role in the selection of suitable treatment and also in the prognosis prediction. Intratumoral heterogeneity plays a key role in the intrinsic and acquired chemoresistance to cytotoxic and targeted therapies. In this review we focus on the mechanisms of intratumoral and inter tumoral heterogeneity and their relationship to the drug resistance. Understanding of the mechanisms and spatiotemporal dynamics of tumor heterogeneity development before and during the therapy is important for the ability to design individual treatment protocols suitable in the given molecular context. (author)

  20. Aggregation Algorithms in Heterogeneous Tables

    Directory of Open Access Journals (Sweden)

    Titus Felix FURTUNA

    2006-01-01

    Full Text Available The heterogeneous tables are most used in the problem of aggregation. A solution for this problem is to standardize these tables of figures. In this paper, we proposed some methods of aggregation based on the hierarchical algorithms.