184,177 research outputs found
To how many politicians should government be left?
The quality of governance of institutions, corporations and countries depends
on the ability of efficient decision making within the respective boards or
cabinets. Opinion formation processes within groups are size dependent. It is
often argued - as now e.g. in the discussion of the future size of the European
Commission - that decision making bodies of a size beyond 20 become strongly
inefficient. We report empirical evidence that the performance of national
governments declines with increasing membership and undergoes a qualitative
change in behavior at a particular group size. We use recent UNDP, World Bank
and CIA data on overall government efficacy, i.e. stability, the quality of
policy formulation as well as human development indices of individual countries
and relate it to the country's cabinet size. We are able to understand our
findings through a simple physical model of opinion dynamics in groups.Comment: main text 5 pages and 4 eps figures, appendi
Ordering dynamics in the voter model with aging
The voter model with memory-dependent dynamics is theoretically and
numerically studied at the mean-field level. The `internal age', or time an
individual spends holding the same state, is added to the set of binary states
of the population, such that the probability of changing state (or activation
probability ) depends on this age. A closed set of integro-differential
equations describing the time evolution of the fraction of individuals with a
given state and age is derived, and from it analytical results are obtained
characterizing the behavior of the system close to the absorbing states. In
general, different age-dependent activation probabilities have different
effects on the dynamics. When the activation probability is an increasing
function of the age , the system reaches a steady state with coexistence of
opinions. In the case of aging, with being a decreasing function, either
the system reaches consensus or it gets trapped in a frozen state, depending on
the value of (zero or not) and the velocity of approaching
. Moreover, when the system reaches consensus, the time ordering of
the system can be exponential () or power-law like ().
Exact conditions for having one or another behavior, together with the
equations and explicit expressions for the exponents, are provided
Opinion Polarization by Learning from Social Feedback
We explore a new mechanism to explain polarization phenomena in opinion
dynamics in which agents evaluate alternative views on the basis of the social
feedback obtained on expressing them. High support of the favored opinion in
the social environment, is treated as a positive feedback which reinforces the
value associated to this opinion. In connected networks of sufficiently high
modularity, different groups of agents can form strong convictions of competing
opinions. Linking the social feedback process to standard equilibrium concepts
we analytically characterize sufficient conditions for the stability of
bi-polarization. While previous models have emphasized the polarization effects
of deliberative argument-based communication, our model highlights an affective
experience-based route to polarization, without assumptions about negative
influence or bounded confidence.Comment: Presented at the Social Simulation Conference (Dublin 2017
Mapping trajectories of becoming: four forms of behaviour in co-housing initiatives
In order learn about planning in a world increasingly characterised by resource interdependencies and a plurality of governing agencies, this paper follows the processes of becoming for two co-housing initiatives.
Self-organisation – understood as the emergence of actor-networks – is the leading theoretical concept, complemented by translation from actor-network theory and individuation from assemblage theory. This theoretical hybrid distinguishes four forms of behaviour (decoding, coding, expansion and contraction) that are used to analyse the dynamics of becoming in the two cases. As a result, information is revealed on the conditions that give rise to co-housing initiatives, and the dynamic interactions between planning authorities, (groups of) initiators and other stakeholders that gave shape to the initiatives. Differences between these actors become blurred, as both try to create meaning and reasoning in a non-linear, complex and uncertain world. The paper concludes with a view on planning as an act
of adaptive navigation, an act equally performed by professionals working for planning authorities and a case initiator
A review on analysis and synthesis of nonlinear stochastic systems with randomly occurring incomplete information
Copyright q 2012 Hongli Dong et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.In the context of systems and control, incomplete information refers to a dynamical system in which knowledge about the system states is limited due to the difficulties in modeling complexity in a quantitative way. The well-known types of incomplete information include parameter uncertainties and norm-bounded nonlinearities. Recently, in response to the development of network technologies, the phenomenon of randomly occurring incomplete information has become more and more prevalent. Such a phenomenon typically appears in a networked environment. Examples include, but are not limited to, randomly occurring uncertainties, randomly occurring nonlinearities, randomly occurring saturation, randomly missing measurements and randomly occurring quantization. Randomly occurring incomplete information, if not properly handled, would seriously deteriorate the performance of a control system. In this paper, we aim to survey some recent advances on the analysis and synthesis problems for nonlinear stochastic systems with randomly occurring incomplete information. The developments of the filtering, control and fault detection problems are systematically reviewed. Latest results on analysis and synthesis of nonlinear stochastic systems are discussed in great detail. In addition, various distributed filtering technologies over sensor networks are highlighted. Finally, some concluding remarks are given and some possible future research directions are pointed out. © 2012 Hongli Dong et al.This work was supported in part by the National Natural Science Foundation of China under Grants 61273156, 61134009, 61273201, 61021002, and 61004067, the Engineering and Physical Sciences Research Council (EPSRC) of the UK under Grant GR/S27658/01, the Royal Society of the UK, the National Science Foundation of the USA under Grant No. HRD-1137732, and the Alexander von Humboldt Foundation of German
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