610,216 research outputs found

    Evolutionary Dynamics of Populations with Conflicting Interactions: Classification and Analytical Treatment Considering Asymmetry and Power

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    Evolutionary game theory has been successfully used to investigate the dynamics of systems, in which many entities have competitive interactions. From a physics point of view, it is interesting to study conditions under which a coordination or cooperation of interacting entities will occur, be it spins, particles, bacteria, animals, or humans. Here, we analyze the case, where the entities are heterogeneous, particularly the case of two populations with conflicting interactions and two possible states. For such systems, explicit mathematical formulas will be determined for the stationary solutions and the associated eigenvalues, which determine their stability. In this way, four different types of system dynamics can be classified, and the various kinds of phase transitions between them will be discussed. While these results are interesting from a physics point of view, they are also relevant for social, economic, and biological systems, as they allow one to understand conditions for (1) the breakdown of cooperation, (2) the coexistence of different behaviors ("subcultures"), (2) the evolution of commonly shared behaviors ("norms"), and (4) the occurrence of polarization or conflict. We point out that norms have a similar function in social systems that forces have in physics

    Formal executable descriptions of biological systems

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    The similarities between systems of living entities and systems of concurrent processes may support biological experiments in silico. Process calculi offer a formal framework to describe biological systems, as well as to analyse their behaviour, both from a qualitative and a quantitative point of view. A couple of little examples help us in showing how this can be done. We mainly focus our attention on the qualitative and quantitative aspects of the considered biological systems, and briefly illustrate which kinds of analysis are possible. We use a known stochastic calculus for the first example. We then present some statistics collected by repeatedly running the specification, that turn out to agree with those obtained by experiments in vivo. Our second example motivates a richer calculus. Its stochastic extension requires a non trivial machinery to faithfully reflect the real dynamic behaviour of biological systems

    The Ontology of Documents

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    As is well known, speech acts such as acts of promising can have ontological consequences. For example an act of promising can give rise to a mutually correlated claim and obligation. Increasingly, speech acts in the narrow sense are being augmented by the use of documents of multiple different sorts. In this paper we analyze the results of this augmenta-tion from the ontological point of view, considering especially the domains of law and com-merce. We show how document acts are not isolated phenomena, but rather form large and complex systems with other entities, including occurrent entities such as acts of signing and inspecting, as well as speech acts for example of instructing people to sign or complete a doc-ument. The paper concludes with a consideration of some of the special problems associated with the use of digital documents, for example as concerns issues of security and provenance

    Rain: Relaxations in the sky

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    We demonstrate how, from the point of view of energy flow through an open system, rain is analogous to many other relaxational processes in Nature such as earthquakes. By identifying rain events as the basic entities of the phenomenon, we show that the number density of rain events per year is inversely proportional to the released water column raised to the power 1.4. This is the rain-equivalent of the Gutenberg-Richter law for earthquakes. The event durations and the waiting times between events are also characterised by scaling regions, where no typical time scale exists. The Hurst exponent of the rain intensity signal H=0.76>0.5H = 0.76 > 0.5. It is valid in the temporal range from minutes up to the full duration of the signal of half a year. All of our findings are consistent with the concept of self-organised criticality, which refers to the tendency of slowly driven non-equilibrium systems towards a state of scale free behaviour.Comment: 9 pages, 8 figures, submitted to PR

    A Socio Religious Analysis of Suicides and its Impact on Economic Development

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    The aim of this paper is to gaining deeper insight into the reasons and consequences of condemned suicidal act from the socio-religious point of view and its impact on the economic development of a society. The condemned act of suicide and problems relating to it, keeping in view the available facts and figures is analysed in view of social and religious beliefs in the known religions of the world. Suicide is a serious public social problem. It is one of the important problems. Different reports on the causes and consequences of suicide have presented an extremely grim picture. It has threatened the life itself. The people resorted to suicides in huge numbers since last decade. Accordingly, the problem of suicide and other related matters may be viewed in terms of the role performance failure of the social & religious systems concerned and the social entities in their environment. Analogously, the problem may be interpreted in terms of the mal-functions of relationships based role on the reciprocity of expectations amongst the interacting social systems.Suicidal, Economics, Socio-religious, Beliefs, Rituals, problems, Reasons, Consequences, Role-Performance, Interaction.

    Plasma-inspired biomaterials

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    The first questions which arise when one looks at the title of this special issue are what are plasma-inspired biomaterials, and what is this Special Issue of Journal of Physics D: Applied Physics (JPhysD) all about? Peculiar as it may seem, from a philosophical point of view 'inspiration' is something that influences by idea or is a good idea that connects two at first glance opposite things—plasma and biomaterials. On the one hand, plasma as a discharge state of the gas is considered nowadays as a cutting edge tool which can manipulate objects at the atomic or molecular scale (figure 1). On the other hand, biomaterials are substances that are engineered to possess certain properties which can control the interactions with components of living systems, inducing favourable response from the biological entities, and as such can direct the course of a therapy or diagnostic procedure [1]. In this respect, plasmas can be used to initiating even more favourable or selective responses, making the biomaterials even more suitable for their interaction biological entitiesPeer ReviewedPostprint (author's final draft

    A Gossip Algorithm based Clock Synchronization Scheme for Smart Grid Applications

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    The uprising interest in multi-agent based networked system, and the numerous number of applications in the distributed control of the smart grid leads us to address the problem of time synchronization in the smart grid. Utility companies look for new packet based time synchronization solutions with Global Positioning System (GPS) level accuracies beyond traditional packet methods such as Network Time Proto- col (NTP). However GPS based solutions have poor reception in indoor environments and dense urban canyons as well as GPS antenna installation might be costly. Some smart grid nodes such as Phasor Measurement Units (PMUs), fault detection, Wide Area Measurement Systems (WAMS) etc., requires synchronous accuracy as low as 1 ms. On the other hand, 1 sec accuracy is acceptable in management information domain. Acknowledging this, in this study, we introduce gossip algorithm based clock synchronization method among network entities from the decision control and communication point of view. Our method synchronizes clock within dense network with a bandwidth limited environment. Our technique has been tested in different kinds of network topologies- complete, star and random geometric network and demonstrated satisfactory performance
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