Connecting the Micro-dynamics to the Emergent Macro-variables: Self-Organized Criticality and Absorbing Phase Transitions in the Deterministic Lattice Gas

We reinvestigate the Deterministic Lattice Gas introduced as a paradigmatic model of the 1/f spectra (Phys. Rev. Lett. V26, 3103 (1990)) arising according to the Self-Organized Criticality scenario. We demonstrate that the density fluctuations exhibit an unexpected dependence on systems size and relate the finding to effective Langevin equations. The low density behavior is controlled by the critical properties of the gas at the absorbing state phase transition. We also show that the Deterministic Lattice Gas is in the Manna universality class of absorbing state phase transitions. This is in contrast to expectations in the literature which suggested that the entirely deterministic nature of the dynamics would put the model in a different universality class. To our knowledge this is the first fully deterministic member of the Manna universality class.Comment: 8 pages, 12 figures. Changes in the new version: Reference list has been correcte

Marketing Challenges and Advertising Partner Selection:Exploring Advertiser-Agency Relationships in the Danish Media Industry

Purpose: Agencies traditionally play the role of intermediaries between advertisers and media. Digital innovations and the rise of media platforms created multiple new channels to reach audiences and therefore provided opportunities and challenges for advertisers. In this research we map out advertisers’ marketing-related challenges and explore how these challenges influence agency partner selection. Methodology: Our study is based on a survey of 146 larger Danish advertisers, using a combination of open and closed questions. An inductive thematic analysis resulted in the identification of 13 different marketing challenges, that we linked to the use of different types of agencies. Closed questions were aimed at identifying for example whether advertisers aim for more in-sourcing, or out-sourcing of marketing activities to agencies. Findings/Contribution: This research firstly reveals the challenges of advertisers in today’s media market. Secondly, we discuss how agencies adopted new business models to answer different needs of their clients. Thirdly, the findings suggest that almost all surveyed advertisers use multiple agencies to solve their marketing challenges but prefer to maintain control over these agencies. The findings update what we know about marketing challenges for advertisers and suggest an altered academic perspective on the complexity around agency selection, and the role of the advertising agency

Connectivity-Driven Coherence in Complex Networks

We study the emergence of coherence in complex networks of mutually coupled non-identical elements. We uncover the precise dependence of the dynamical coherence on the network connectivity, on the isolated dynamics of the elements and the coupling function. These findings predict that in random graphs, the enhancement of coherence is proportional to the mean degree. In locally connected networks, coherence is no longer controlled by the mean degree, but rather on how the mean degree scales with the network size. In these networks, even when the coherence is absent, adding a fraction s of random connections leads to an enhancement of coherence proportional to s. Our results provide a way to control the emergent properties by the manipulation of the dynamics of the elements and the network connectivity.Comment: 4 pages, 2 figure

Cluster geometry and survival probability in systems driven by reaction-diffusion dynamics

We consider a reaction-diffusion model incorporating the reactions A -> 0, A -> 2A and 2A -> 3A. Depending on the relative rates for sexual and asexual reproduction of the quantity A, the model exhibits either a continuous or first-order absorbing phase transition to an extinct state. A tricritical point separates the two phase lines. As well as briefly examining this critical behavior in 2+1 dimensions, we pay particular attention to the cluster geometry. We observe the different cluster structures that form at criticality for the three different types of critical behavior and show that there exists a linear relationship for the probability of survival against initial cluster size at the tricritical point only.Comment: 4 pages, 6 figure

Tempo and Mode of Evolution in the Tangled Nature Model

We study the Tangled Nature model of macro evolution and demonstrate that the co-evolutionary dynamics produces an increasingly correlated core of well occupied types. At the same time the entire configuration of types becomes increasing de-correlated. This finding is related to ecosystem evolution. The systems level dynamics of the model is subordinated to intermittent transitions between meta-stable states. We improve on previous studies of the statistics of the transition times and show that the fluctuations in the offspring probability decreases with number of transitions. The longtime adaptation, as seen by an increasing population size is demonstrated to be related to the convexity of the offspring probability. We explain how the models behaviour is a mathematical reflection of Darwin's concept of adaptation of profitable variations.Comment: 6 pages, 5 figure