3,110 research outputs found
Entropy in Image Analysis II
Image analysis is a fundamental task for any application where extracting information from images is required. The analysis requires highly sophisticated numerical and analytical methods, particularly for those applications in medicine, security, and other fields where the results of the processing consist of data of vital importance. This fact is evident from all the articles composing the Special Issue "Entropy in Image Analysis II", in which the authors used widely tested methods to verify their results. In the process of reading the present volume, the reader will appreciate the richness of their methods and applications, in particular for medical imaging and image security, and a remarkable cross-fertilization among the proposed research areas
Clustering-based Identification of Precursors of Extreme Events in Chaotic Systems
Abrupt and rapid high-amplitude changes in a dynamical system's states known
as extreme event appear in many processes occurring in nature, such as drastic
climate patterns, rogue waves, or avalanches. These events often entail
catastrophic effects, therefore their description and prediction is of great
importance. However, because of their chaotic nature, their modelling
represents a great challenge up to this day. The applicability of a data-driven
modularity-based clustering technique to identify precursors of rare and
extreme events in chaotic systems is here explored. The proposed identification
framework based on clustering of system states, probability transition matrices
and state space tessellation was developed and tested on two different chaotic
systems that exhibit extreme events: the Moehliss-Faisst-Eckhardt model of
self-sustained turbulence and the 2D Kolmogorov flow. Both exhibit extreme
events in the form of bursts in kinetic energy and dissipation. It is shown
that the proposed framework provides a way to identify pathways towards extreme
events and predict their occurrence from a probabilistic standpoint. The
clustering algorithm correctly identifies the precursor states leading to
extreme events and allows for a statistical description of the system's states
and its precursors to extreme events
The Role of Europe in World-Wide Science and Technology: Monitoring and Evaluation in a Context of Global Competition
Noyons ECM, Buter RK, van Raan AFJ, Schwechheimer H, Winterhager M, Weingart P. The Role of Europe in World-Wide Science and Technology: Monitoring and Evaluation in a Context of Global Competition. Leiden: Universiteit Leiden; 2000
Challenges in Complex Systems Science
FuturICT foundations are social science, complex systems science, and ICT.
The main concerns and challenges in the science of complex systems in the
context of FuturICT are laid out in this paper with special emphasis on the
Complex Systems route to Social Sciences. This include complex systems having:
many heterogeneous interacting parts; multiple scales; complicated transition
laws; unexpected or unpredicted emergence; sensitive dependence on initial
conditions; path-dependent dynamics; networked hierarchical connectivities;
interaction of autonomous agents; self-organisation; non-equilibrium dynamics;
combinatorial explosion; adaptivity to changing environments; co-evolving
subsystems; ill-defined boundaries; and multilevel dynamics. In this context,
science is seen as the process of abstracting the dynamics of systems from
data. This presents many challenges including: data gathering by large-scale
experiment, participatory sensing and social computation, managing huge
distributed dynamic and heterogeneous databases; moving from data to dynamical
models, going beyond correlations to cause-effect relationships, understanding
the relationship between simple and comprehensive models with appropriate
choices of variables, ensemble modeling and data assimilation, modeling systems
of systems of systems with many levels between micro and macro; and formulating
new approaches to prediction, forecasting, and risk, especially in systems that
can reflect on and change their behaviour in response to predictions, and
systems whose apparently predictable behaviour is disrupted by apparently
unpredictable rare or extreme events. These challenges are part of the FuturICT
agenda
Understanding The Impact Of Virtual-Mirroring Based Learning On Collaboration In A Data And Analytics Function: A Resilience Perspective
Large multinational organizations are struggling to adapt and innovate in the face of increasing turbulence, uncertainty, and complexity. The lack of adaptive capacity is one of the major risks facing such organizations as the rapid change in technology, urbanization, socio-economic trends, and regulations continues to accelerate and outpace their ability to adapt. This is a resilience problem that organizations are addressing by investing in Data and Analytics to improve their innovation and competitive capabilities. However, Data and Analytics projects are more likely to fail than to succeed. Competing on data and analytics is not only a technical challenge but also a challenge in promoting collaborative innovation networks that are based on two key characteristics of resilient systems. One characteristic is the ability to learn while the second is the ability to foster diversity.
In this study, we examine how a newly-established Data and Analytics function has evolved over a one-year period. First, we conduct a baseline survey with two sections. The first section captures the structure of Innovation, Expertise, and Projects networks using network science techniques. In the second section we extract four resilience-based workstyles that provide a behavioral representation of each phase of the Adaptive Cycle Theory. Following the survey, we conduct a controlled experiment where the Data and Analytics population is divided into four groups. One group acts as control mechanism while the remaining three groups are exposed to three different Virtual-Mirroring-Based Learning (VMBL) interventions. A virtual-mirror, which is a visualization of an employee’s own social network that provides a self-reflection as a learning process. The premise is that exposure to such self-insights leads to a change in collaborative behavior. After a period of nine months, the baseline survey is repeated and then the effects of the interventions are analyzed.
The findings provided original insights into the evolution of the Data and Analytics function, the characteristics of an effective VMBL design, and the relationship between resilience-based workstyles and brokerage roles in social networks. The applied and theoretical contributions of this research provide a template for practitioners while advancing the theory and measurement of resilience
Smart Manufacturing
This book is a collection of 11 articles that are published in the corresponding Machines Special Issue “Smart Manufacturing”. It represents the quality, breadth and depth of the most updated study in smart manufacturing (SM); in particular, digital technologies are deployed to enhance system smartness by (1) empowering physical resources in production, (2) utilizing virtual and dynamic assets over the Internet to expand system capabilities, (3) supporting data-driven decision-making activities at various domains and levels of businesses, or (4) reconfiguring systems to adapt to changes and uncertainties. System smartness can be evaluated by one or a combination of performance metrics such as degree of automation, cost-effectiveness, leanness, robustness, flexibility, adaptability, sustainability, and resilience. This book features, firstly, the concepts digital triad (DT-II) and Internet of digital triad things (IoDTT), proposed to deal with the complexity, dynamics, and scalability of complex systems simultaneously. This book also features a comprehensive survey of the applications of digital technologies in space instruments; a systematic literature search method is used to investigate the impact of product design and innovation on the development of space instruments. In addition, the survey provides important information and critical considerations for using cutting edge digital technologies in designing and manufacturing space instruments
Motif formation and emergence of mesoscopic structure in complex networks
PhDNetwork structures can encode information from datasets that have a natural representation
in terms of networks, for example datasets describing collaborations or social
relations among individuals in science or society, as well as from data that can be mapped
into graphs due to their intrinsic correlations, such as time series or images. Developing
models and algorithms to characterise the structure of complex networks at the micro
and mesoscale is thus of fundamental importance to extract relevant information from
and to understand real world complex data and systems. In this thesis we will investigate
how modularity, a mesoscopic feature observed almost universally in real world
complex networks can emerge, and how this phenomenon is related to the appearance of
a particular type of network motif, the triad. We will shed light on the role that motifs
play in shaping the mesoscale structure of complex networks by considering two special
classes of networks, multiplex networks, that describe complex systems where interactions
of different nature are involved, and visibility graphs, a family of graphs that can
be extracted from the time series of dynamical processes. This thesis is based on the
research papers listed below, in particular on the first five, published between 2014 and
2016:
1. Bianconi, G., Darst R. K., Iacovacci J., Fortunato S., Triadic closure as a basic generating
mechanism of communities in complex networks, Phys. Rev. E 90 (4), 042806
(2014).
2. Iacovacci J., Wu Z., Bianconi G., Mesoscopic structures reveal the network between
the layers of multiplex data sets, Phys. Rev. E. 92 (4), 042806 (2015).
3. Battiston F., Iacovacci J., Nicosia V., Bianconi G., Latora V., Emergence of multiplex
communities in collaboration networks, PloS one 11 (1), e0147451 (2016).
4. Iacovacci J., Lacasa L., Sequential visibility-graph motifs, Phys. Rev. E. 93 (4),
042309 (2016).
5. Iacovacci J., Lacasa L., Sequential motif pro le of natural visibility-graphs, Phys.
Rev. E. 94 (5), 052309 (2016).
6. Iacovacci J., Bianconi G., Extracting information from multiplex networks, Chaos:
An Interdisciplinary Journal of Nonlinear Science 26 (6), 065306 (2016).
7. Iacovacci J., Rahmede C., Arenas A., Bianconi G., Functional Multiplex PageRank,
EPL (Europhysics Letters) 116(2), 28004 (2016).
8. Lacasa L, Iacovacci J., Visibility graphs of random scalar elds and spatial data,
arXiv preprint arXiv:1702.07813 (2017).
9. Rahmede C, Iacovacci J, Arenas A, Bianconi G., Centralities of Nodes and In
infuences of Layers in Large Multiplex Network, arXiv preprint arXiv:1703.05833 (2017)
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