Search results for "Complex system"
showing 10 items of 226 documents
Identifying Early Warning Signals for the Sudden Transition from Mild to Severe Tobacco Etch Disease by Dynamical Network Biomarkers
2019
This article belongs to the Special Issue The Complexity of the Potyviral Interaction Network.
A Meta-Model for Intelligent Engineering Design of Complex City
2019
A city is a complex system, requiring the input of multiple disciplines for its (re)design. It shares some properties of two kinds of objects: empirical objects as well as theoretical objects. As city emerges as a complex object for multi-disciplinary studies, it is of the highest importance to adopt a systemic and global approach in order to bring new knowledge to this field. To master the growing complexity of cities and to consider in the same spot heterogeneous ways of thinking of city, we need intellectual tools and models. The goal of this paper is to propose a model for describing engineering modelling knowledge with relationships and transformations between four domains: (1) citizen…
Applying System Dynamics Modelling to Strategic Management: A Literature Review
2016
System dynamics (SD) has been proved to be a useful methodology to support both understanding and learning processes of complex systems and phenomena. Since its origin, SD has been successfully applied to many different fields of studies (e.g. climate change, physics, engineering, environmental sciences, economics, management, etc.). Among these, strategic management (SM) has a particular relevance as testified by several streams of research that originate from the combination between SD modelling and SM. The aim of this paper is to explore and discuss the theoretical and empirical development of SD in the SM field through a systematic analysis of the literature in order to highlight the ma…
Understanding the Importance of Proper Incentives for Critical Infrastructures Management – How System Dynamics Can Help
2016
International audience; Computer and information systems are now at the core of numerous critical infrastructures. However, their security management is by far not a trivial issue. Further, these systems, by their very nature, belong to the domain of complex systems, where system dynamics (SD) is an established method, which aims at modelling such systems, their analysis and understanding. Further, on this basis it enables simulation of various policies to properly manage complex systems. More precisely, through understanding of the basic elements of the whole mosaic and their interplay, proper incentives can be tested. And this is important, because proper incentives can lead to the desire…
The Hidden Charm of Life
2019
Synthetic biology is an engineering view on biotechnology, which has revolutionized genetic engineering. The field has seen a constant development of metaphors that tend to highlight the similarities of cells with machines. I argue here that living organisms, particularly bacterial cells, are not machine-like, engineerable entities, but, instead, factory-like complex systems shaped by evolution. A change of the comparative paradigm in synthetic biology from machines to factories, from hardware to software, and from informatics to economy is discussed.
2016
AbstractThe different factors involved in the growth process of complex networks imprint valuable information in their observable topologies. How to exploit this information to accurately predict structural network changes is the subject of active research. A recent model of network growth sustains that the emergence of properties common to most complex systems is the result of certain trade-offs between node birth-time and similarity. This model has a geometric interpretation in hyperbolic space, where distances between nodes abstract this optimisation process. Current methods for network hyperbolic embedding search for node coordinates that maximise the likelihood that the network was pro…
Three-dimensional multiple-particle tracking with nanometric precision over tunable axial ranges
2017
The precise localization of nanometric objects in three dimensions is essential to identify functional diffusion mechanisms in complex systems at the cellular or molecular level. However, most optical methods can achieve high temporal resolution and high localization precision only in two dimensions or over a limited axial (z) range. Here we develop a novel wide-field detection system based on an electrically tunable lens that can track multiple individual nanoscale emitters in three dimensions over a tunable axial range with nanometric localization precision. The optical principle of the technique is based on the simultaneous acquisition of two images with an extended depth of field while …
Statistical characterization of deviations from planned flight trajectories in air traffic management
2016
Understanding the relation between planned and realized flight trajectories and the determinants of flight deviations is of great importance in air traffic management. In this paper we perform an in depth investigation of the statistical properties of planned and realized air traffic on the German airspace during a 28 day periods, corresponding to an AIRAC cycle. We find that realized trajectories are on average shorter than planned ones and this effect is stronger during night-time than daytime. Flights are more frequently deviated close to the departure airport and at a relatively large angle to destination. Moreover, the probability of a deviation is higher in low traffic phases. All the…
Gene-based and semantic structure of the Gene Ontology as a complex network
2012
The last decade has seen the advent and consolidation of ontology based tools for the identification and biological interpretation of classes of genes, such as the Gene Ontology. The information accumulated time-by-time and included in the GO is encoded in the definition of terms and in the setting up of semantic relations amongst terms. This approach might be usefully complemented by a bottom-up approach based on the knowledge of relationships amongst genes. To this end, we investigate the Gene Ontology from a complex network perspective. We consider the semantic network of terms naturally associated with the semantic relationships provided by the Gene Ontology consortium and a gene-based …
The latent geometry of the human protein interaction network
2017
Abstract Motivation A series of recently introduced algorithms and models advocates for the existence of a hyperbolic geometry underlying the network representation of complex systems. Since the human protein interaction network (hPIN) has a complex architecture, we hypothesized that uncovering its latent geometry could ease challenging problems in systems biology, translating them into measuring distances between proteins. Results We embedded the hPIN to hyperbolic space and found that the inferred coordinates of nodes capture biologically relevant features, like protein age, function and cellular localization. This means that the representation of the hPIN in the two-dimensional hyperboli…