Publications
Exogenous coordination in multi-scale systems: How information flows and timing affect system properties Journal Article
Diaconescu, Ada; Felice, Louisa Jane Di; Mellodge, Patricia
In: Future Generation Computer Systems, 114 , pp. 403–426, 2021, ISSN: 0167739X.
Abstract | Links | BibTeX | Tags: Complex system, Control feedback, Hierarchy Theory, Information flows, Multi-scale coordination, Resource analysis, State abstraction
@article{Diaconescu2021,
title = {Exogenous coordination in multi-scale systems: How information flows and timing affect system properties},
author = {Ada Diaconescu and Louisa Jane Di Felice and Patricia Mellodge},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167739X20304726},
doi = {10.1016/j.future.2020.07.034},
issn = {0167739X},
year = {2021},
date = {2021-01-01},
journal = {Future Generation Computer Systems},
volume = {114},
pages = {403--426},
publisher = {North-Holland},
abstract = {The architecture of coordination mechanisms is central to the performance and behaviour of (self-)integrated systems across natural, socio-technical and cyber\textendashphysical domains. Multi-scale coordination schemes are prevalent in large-scale systems with bounded performance requirements and limited resource constraints. However, theories to formalise how coordination can be implemented across multi-scale systems are often domain-specific, lacking generic, reusable principles. In these systems, feedback among system entities is a key component to coordination. Building on theories of hierarchies and complexity, in previous work we formalised Multi-Scale Abstraction Feedbacks (MSAF) as a design pattern to describe the architecture of feedback across system scales, highlighting the role played by micro-entities and macro-entities, as well as their interconnections. Focusing on exogenous coordination, this paper refines the MSAF pattern, describing a feedback cycle across scales as one where information flows bottom-up and top-down through five actions: state information communication, state information abstraction, information processing, control information communication, and adaptation from control information. Abstracted state information at each scale is processed with control input from the scale above and provides control input to the scale below. Using the example of distributed task allocation through exogenous coordination, NetLogo simulations are implemented to analyse the impact that different exogenous coordination strategies, and their internal timing configurations, have on resource consumption and on convergence performance. The experimental insights and refinement of the MSAF pattern contribute to a general theory of multi-scale feedback and adaptation. This architectural pattern and associated analysis and evaluation tools are still developing, but offer a concrete basis for further expansion, improvement, and implementation, while addressing questions that are at the core of the behaviour of multi-scale systems.},
keywords = {Complex system, Control feedback, Hierarchy Theory, Information flows, Multi-scale coordination, Resource analysis, State abstraction},
pubstate = {published},
tppubtype = {article}
}
An alternative to market-oriented energy models: Nexus patterns across hierarchical levels Journal Article
Felice, Louisa Jane Di; Ripa, Maddalena; Giampietro, Mario
In: Energy Policy, 126 , pp. 431–443, 2019, ISSN: 03014215.
Abstract | Links | BibTeX | Tags: Complexity, Hierarchy Theory, MuSIASEM, Science-policy interface, Societal metabolism, Water-energy-food nexus
@article{DiFelice2019,
title = {An alternative to market-oriented energy models: Nexus patterns across hierarchical levels},
author = {Louisa Jane Di Felice and Maddalena Ripa and Mario Giampietro},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0301421518307250},
doi = {10.1016/j.enpol.2018.11.002},
issn = {03014215},
year = {2019},
date = {2019-03-01},
journal = {Energy Policy},
volume = {126},
pages = {431--443},
publisher = {Elsevier Ltd},
abstract = {From a biophysical perspective, energy is central to the behaviour of social-ecological systems. Its ubiquity means that energy is entangled with nexus elements, including water, land, emissions and labour. At the science-policy interface, large market-oriented energy models dominate as the tool to inform decision-making. The outputs of these models are used to shape policies, but strongly depend on sets of assumptions that are not available for deliberation and gloss over uncertainties. Taking an approach from complexity, we propose an alternative to market-oriented energy models, describing the behaviour of energy systems in relation to patterns of nexus elements across hierarchical levels. Three characteristics are central to the approach: (i) the distinction of the model's building blocks into functional and structural elements; (ii) their hierarchical organisation and (iii) the description of nexus patterns at each level, through the tool of the processor. To illustrate the model, it is applied to Catalonia's energy sector, linking production and consumption patterns. The framework may help inform stakeholder deliberation on pressing energy and nexus issues.},
keywords = {Complexity, Hierarchy Theory, MuSIASEM, Science-policy interface, Societal metabolism, Water-energy-food nexus},
pubstate = {published},
tppubtype = {article}
}
The unresolved controversy over nuclear power: A new approach from complexity theory Journal Article
Diaz-Maurin, François; Kovacic, Zora
In: Global Environmental Change, 31 , pp. 207–216, 2015, ISSN: 09593780.
Abstract | Links | BibTeX | Tags: Epistemology, Hierarchy Theory, Historical analysis, Nuclear energy, Science for governance, Technology choice
@article{Diaz-Maurin2015,
title = {The unresolved controversy over nuclear power: A new approach from complexity theory},
author = {Fran\c{c}ois Diaz-Maurin and Zora Kovacic},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0959378015000163},
doi = {10.1016/j.gloenvcha.2015.01.014},
issn = {09593780},
year = {2015},
date = {2015-03-01},
journal = {Global Environmental Change},
volume = {31},
pages = {207--216},
publisher = {Pergamon},
abstract = {We explore the controversy over nuclear power by looking at the plurality of narratives that have emerged throughout its history. We find a lack of consistency between the visions of nuclear power put forward by governments and industry and the experience associated with economic viability, nuclear accidents, waste handling, and so on. We use the conceptual tool of holon from complexity theory to provide a link between the models used for the governance of nuclear power and the realization of those models. The analysis of the holon over time reveals a systemic inconsistency between the way in which the story about nuclear energy is told and the experience gained after implementing nuclear energy according to the story. This inconsistency is due to the incompatible levels of observation used by different social actors endorsing different perspectives. The implementation of nuclear power has been based on the engineering view, focusing on the functioning of the nuclear power plant considered in abstraction from the wider implications of the adoption of this technology on the environment, on the economy, and on society. We cross-check this narrative with the societal metabolism view in order to provide a long term perspective of the interdependencies between nuclear power and the complex socio-economic system in which it is embedded. We conclude that the controversy over nuclear power may be treated as a problem of contrasting beliefs and normative values in clear disjunction from experience. The analysis presented in this paper suggests that more attention should be given to the quality of the narratives used in policy making.},
keywords = {Epistemology, Hierarchy Theory, Historical analysis, Nuclear energy, Science for governance, Technology choice},
pubstate = {published},
tppubtype = {article}
}
Holons, creaons, genons, environs, in hierarchy theory: Where we have gone Journal Article
Allen, Timothy; Giampietro, Mario
In: Ecological Modelling, 293 , pp. 31–41, 2014, ISSN: 03043800.
Abstract | Links | BibTeX | Tags: Complexity, Hierarchy Theory, Holon, Narrative, Network ecology, Systems analysis
@article{Allen2014,
title = {Holons, creaons, genons, environs, in hierarchy theory: Where we have gone},
author = {Timothy Allen and Mario Giampietro},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0304380014002993},
doi = {10.1016/j.ecolmodel.2014.06.017},
issn = {03043800},
year = {2014},
date = {2014-12-01},
journal = {Ecological Modelling},
volume = {293},
pages = {31--41},
publisher = {Elsevier},
abstract = {This paper compares and contrasts hierarchy theory and network theory, with the purpose of instructing practitioners in both fields, particularly network theorist, as to how each might relate, and translate to the other. Hierarchy theory and network theory are distinctive but twins. Network theory works its way upscale, incrementally, while hierarchy theory reaches upscale, happy to redefine situations at each new level. Both theories are distinguished from most others in their use of holons. Holons are the vehicle used in this paper to tie network and hierarchy theory together, and show how working in tandem they can advance complexity theory in biology in general. Holons are dual structures that embody contradiction in simultaneous wholeness and partness. Patten defines holons in terms of how they function, and in this way he translates across levels with explicit steps. He does this by specifying the input environs (environment) to feed creaons, the input points of holons. The output environ is fed by the holon's genon, the points of output. These steps limit the rescaling of network theory, but allow quantification all the way. Hierarchy theory is not so limited in rescaling, but it pays the price of limiting quantification across levels. Hierarchy theory reaches further upscale with set theoretic devices that make it robust across many levels. It is explicit about the categories. Networks are internally consistent and so present models, the dualities of holons notwithstanding. When inconsistency looms, hierarchy theory moves to narratives, which do not have to be consistent, as models must. In a new elaboration of holon here, hierarchy theory identifies an energy/matter half separate from a coded information half. There are three processes: creating, becoming something else, and narrating to the world; all three progress at their own rates, associated with different causalities. It all maps onto taxon, creaon, genon, and environs, emphasizing the larger unity of network and hierarchy theory. Biological and ecological sub-disciplines map onto different parts of the holon. There is also a new theory of how observer decisions are critical in holons. The move between levels that characterizes complexity causes complex systems to become undefinable. With regard to that issue hierarchy theory offers the robustness of narrative form, while network theory hangs on to definitions as long as it can. As hierarchy theory moves upscale, fixed parameters become variables and lose their constancy. In this way structures melt into behavior of some yet higher level structure. Hierarchy theory considers melting structure as being no problem, while network theory ignores the fact that just beyond its purview, structures do indeed melt. So we need hierarchy theory and network theory in tandem to make network theory bolder, and hierarchy theory more tractably quantitative.},
keywords = {Complexity, Hierarchy Theory, Holon, Narrative, Network ecology, Systems analysis},
pubstate = {published},
tppubtype = {article}
}
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