Search results for " Complex System"

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 …

Los programas de cumplimiento penal : Aspectos generales

2021

In Spain, as in many other countries, corporate criminal liability has been a reality for years, as well as criminal compliance programs that allow them to be mitigated or exonerated from liability. In this article we will present some of the main keys to consider for the implementation of these mechanisms. This is a series of general considerations that can serve as a guide to understand the complex system of crime prevention provided by the organization and management models in the corporate environment.

ELSA air traffic simulator: An empirically grounded agent based model for the SESAR scenario

2015

This paper describes the Air Traffic Simulator produced by the ELSA project. It is partially based on interacting agents taking actions during strategic and tactical phases: air companies, network manager, pilots, and controllers. The simulator is highly modular and each part can be used independently of the others. The code is open source, ready to use and available for the research community. Some results concerning the future organization of the European Airspace (free-routing) are presented, using the full capabilities of the model. We found that the implementation of free-routing could have a positive impact on the safety event occurrences that will be reduced in number although spread…

Coupling and Complexity of Interaction of STCA Networks

2009

This paper provides an overview on the results of an ENAV feasibility study, where we exploited an automatic safety data gathering tool to analyze the ATM system performances. In particular, it addresses the use of the EUROCONTROL tool, ASMT (Automatic Safety Monitoring Tool), as a support to monitor STCA performance. The contribution of this study is to explore how analysis methods derived from complex systems theory (i.e. network analysis) can assist in the understanding, monitoring and management of the performance of ATM systems. Our data show that a large number of STCAs do not occur in isolation, but rather that in roughly half of the cases the aircraft involved in an STCA are subsequ…

The Complex System Theory for the Analysis of Inter-Firm Networks: A Literature Overview and Theoretic Framework

2011

In this paper we discuss the body of knowledge known as complex system theory and its relevance to the analysis of inter-firm networks. We start by addressing the development of systems thinking. Through a literature overview, we point out the main elements for the development of systemic thought from its beginning, through its application in business sciences, to the birth of Complex Systems Theory (CST). With these initial annotations we provide an introduction to the concepts of the complex systems theory. We will underscore those aspects of CST that can be useful to analyze inter-firm networks, in order to highlight the evolutionary dynamics of the networks and to clarify the logical li…

Editorial of Critical Phenomena and Diffusion in Complex Systems

2008

An empirically grounded agent based model for modeling directs, conflict detection and resolution operations in air traffic management

2017

We present an agent based model of the Air Traffic Management socio-technical complex system that aims at modeling the interactions between aircrafts and air traffic controllers at a tactical level. The core of the model is given by the conflict detection and resolution module and by the directs module. Directs are flight shortcuts that are given by air controllers to speed up the passage of an aircraft within a certain airspace and therefore to facilitate airline operations. Conflicts resolution between flight trajectories can arise during the en-route phase of each flight due to both not detailed flight trajectory planning or unforeseen events that perturb the planned flight plan. Our mod…

Ecological Complex Systems

2008

Main aim of this topical issue is to report recent advances in noisy nonequilibrium processes useful to describe the dynamics of ecological systems and to address the mechanisms of spatio-temporal pattern formation in ecology both from the experimental and theoretical points of view. This is in order to understand the dynamical behaviour of ecological complex systems through the interplay between nonlinearity, noise, random and periodic environmental interactions. Discovering the microscopic rules and the local interactions which lead to the emergence of specific global patterns or global dynamical behaviour and the noises role in the nonlinear dynamics is an important, key aspect to unders…

Multi-scale analysis of the European airspace using network community detection

2014

We show that the European airspace can be represented as a multi-scale traffic network whose nodes are airports, sectors, or navigation points and links are defined and weighted according to the traffic of flights between the nodes. By using a unique database of the air traffic in the European airspace, we investigate the architecture of these networks with a special emphasis on their community structure. We propose that unsupervised network community detection algorithms can be used to monitor the current use of the airspaces and improve it by guiding the design of new ones. Specifically, we compare the performance of three community detection algorithms, also by using a null model which t…