Remember me

Register  |   Lost password?


 

Recent members

 

 

Show:
Complexity Digest wrote a new blog post titled The Discrete Charm of the Machine: Why the World Became Digital (Kenneth Steiglitz)
A few short decades ago, we were informed by the smooth signals of analog television and radio; we communicated using our analog telephones; and we even computed with analog computers. Today our world is digital, built with zeros and ones. Why did this revolution occur? The Discrete Charm of the Machine explains, in an engaging and accessible manner, the varied physical and logical reasons behind this radical transformation. The spark of individual genius shines through this story of innovation: the stored program of Jacquard’s loom; Charles Babbage’s logical branching; Alan Turing’s...
58 days ago
Complexity Digest wrote a new blog post titled Viruses as Complex Adaptive Systems (Ricard Solé & Santiago F. Elena)
Viruses are everywhere, infecting all sorts of living organisms, from the tiniest bacteria to the largest mammals. Many are harmful parasites, but viruses also play a major role as drivers of our evolution as a species and are essential regulators of the composition and complexity of ecosystems on a global scale. This concise book draws on complex systems theory to provide a fresh look at viral origins, populations, and evolution, and the coevolutionary dynamics of viruses and their hosts. New viruses continue to emerge that threaten people, crops, and farm animals. Viruses constantly evade...
58 days ago
Complexity Digest wrote a new blog post titled Multiplex Networks: Basic Formalism and Structural Properties
This book provides the basis of a formal language and explores its possibilities in the characterization of multiplex networks. Armed with the formalism developed, the authors define structural metrics for multiplex networks. A methodology to generalize monoplex structural metrics to multiplex networks is also presented so that the reader will be able to generalize other metrics of interest in a systematic way. Therefore, this book will serve as a guide for the theoretical development of new multiplex metrics. Furthermore, this Brief describes the spectral properties of these networks in...
58 days ago
Complexity Digest wrote a new blog post titled A collaborative multiyear, multimodel assessment of seasonal influenza forecasting in the United States
Accurate prediction of the size and timing of infectious disease outbreaks could help public health officials in planning an appropriate response. This paper compares approaches developed by five different research groups to forecast seasonal influenza outbreaks in real time in the United States. Many of the models show more accurate forecasts than a historical baseline. A major impediment to predictive ability was the real-time accuracy of available data. The field of infectious disease forecasting is in its infancy and we expect that innovation will spur improvements in forecasting in the...
58 days ago
Complexity Digest wrote a new blog post titled Large teams develop and small teams disrupt science and technology
One of the most universal trends in science and technology today is the growth of large teams in all areas, as solitary researchers and small teams diminish in prevalence1,2,3. Increases in team size have been attributed to the specialization of scientific activities3, improvements in communication technology4,5, or the complexity of modern problems that require interdisciplinary solutions6,7,8. This shift in team size raises the question of whether and how the character of the science and technology produced by large teams differs from that of small teams. Here we analyse more than 65...
58 days ago
Complexity Digest wrote a new blog post titled NECSI Summer School
Gain new insights that reframe your thinking, specific tools to advance current projects, and perspectives to set new directions. Dates: June 2 – 14, 2019Location: MIT, Cambridge, MA The NECSI Summer School offers two intensive week-long courses on complexity science: modeling and networks, and data analytics. You may register for any of the weeks. If desired, arrangements for credit at a home institution may be made in advance. Lab 1: June 2 CX102: Computer Programming for Complex SystemsWeek 1: June 3-7 CX201B: Concepts and ModelingLab 2: June 9 CX103: Setting up for Data...
58 days ago
Complexity Digest wrote a new blog post titled Percolation and the Effective Structure of Complex Networks
Analytical approaches to model the structure of complex networks can be distinguished into two groups according to whether they consider an intensive (e.g., fixed degree sequence and random otherwise) or an extensive (e.g., adjacency matrix) description of the network structure. While extensive approaches—such as the state-of-the-art message passing approximation—typically yield more accurate predictions, intensive approaches provide crucial insights on the role played by any given structural property in the outcome of dynamical processes. Here we introduce an intensive description that...
58 days ago
Complexity Digest wrote a new blog post titled Detecting sequences of system states in temporal networks
Many time-evolving systems in nature, society and technology leave traces of the interactions within them. These interactions form temporal networks that reflect the states of the systems. In this work, we pursue a coarse-grained description of these systems by proposing a method to assign discrete states to the systems and inferring the sequence of such states from the data. Such states could, for example, correspond to a mental state (as inferred from neuroimaging data) or the operational state of an organization (as inferred by interpersonal communication). Our method combines a graph...
58 days ago
Complexity Digest wrote a new blog post titled Continuous versus Discontinuous Transitions in the $D$-Dimensional Generalized Kuramoto Model: Odd $D$ is Different
The Kuramoto model, originally proposed to model the dynamics of many interacting oscillators, has been used and generalized for a wide range of applications involving the collective behavior of large heterogeneous groups of dynamical units whose states are characterized by a scalar angle variable. One such application in which we are interested is the alignment of orientation vectors among members of a swarm. Despite being commonly used for this purpose, the Kuramoto model can only describe swarms in two dimensions, and hence the results obtained do not apply to the often relevant situation...
58 days ago
Complexity Digest wrote a new blog post titled The Multilayer Structure of Corporate Networks
Various company interactions can be described by networks, for instance the ownership networks and the board membership networks. To understand the ecosystem of companies, these interactions cannot be seen in isolation. For this purpose we construct a new multilayer network of interactions between companies in Germany and in the United Kingdom, combining ownership links, social ties through joint board directors, R\&D collaborations and stock correlations in one linked multiplex dataset. We describe the features of this network and show there exists a non-trivial overlap between these...
58 days ago
Complexity Digest wrote a new blog post titled Fake news on Twitter during the 2016 U.S. presidential election
The spread of fake news on social media became a public concern in the United States after the 2016 presidential election. We examined exposure to and sharing of fake news by registered voters on Twitter and found that engagement with fake news sources was extremely concentrated. Only 1% of individuals accounted for 80% of fake news source exposures, and 0.1% accounted for nearly 80% of fake news sources shared. Individuals most likely to engage with fake news sources were conservative leaning, older, and highly engaged with political news. A cluster of fake news sources shared overlapping...
58 days ago
Complexity Digest wrote a new blog post titled Complex Networks: Theory, Methods, and Applications – Lake Como School of Advanced Studies – May 13-17, 2019
Complex networks: theory, methods, and applications (5th edition)Villa del Grumello, Como, Italy, May 13-17, 2019 Many real systems can be modeled as networks, where the elements of the system are nodes and interactions between elements are edges. An even larger set of systems can be modeled using dynamical processes on networks, which are in turn affected by the dynamics. Networks thus represent the backbone of many complex systems, and their theoretical and computational analysis makes it possible to gain insights into numerous applications. Networks permeate almost every conceivable...
58 days ago
Complexity Digest wrote a new blog post titled Narrating Complexity (edited by Richard Walsh & Susan Stepney)
This book stages a dialogue between international researchers from the broad fields of complexity science and narrative studies. It presents an edited collection of chapters on aspects of how narrative theory from the humanities may be exploited to understand, explain, describe, and communicate aspects of complex systems, such as their emergent properties, feedbacks, and downwards causation; and how ideas from complexity science can inform narrative theory, and help explain, understand, and construct new, more complex models of narrative as a cognitive faculty and as a pervasive cultural form...
58 days ago
Complexity Digest wrote a new blog post titled Economic Foundations for Social Complexity Science: Theory, Sentiments, and Empirical Laws (edited by Yuji Aruka & Alan Kirman)
This book focuses on how important massive information is and how sensitive outcomes are to information. In this century humans now are coming up against the massive utilization of information in various contexts. The advent of super intelligence is drastically accelerating the evolution of the socio-economic system. Our traditional analytic approach must therefore be radically reformed in order to adapt to an information-sensitive framework, which means giving up myopic purification and the elimination of all considerations of massive information. In this book, authors who have shared and...
58 days ago
Complexity Digest wrote a new blog post titled The Goodness Paradox: The Strange Relationship Between Virtue and Violence in Human Evolution (Richard Wrangham)
We Homo sapiens can be the nicest of species and also the nastiest. What occurred during human evolution to account for this paradox? What are the two kinds of aggression that primates are prone to, and why did each evolve separately? How does the intensity of violence among humans compare with the aggressive behavior of other primates? How did humans domesticate themselves? And how were the acquisition of language and the practice of capital punishment determining factors in the rise of culture and civilization? Authoritative, provocative, and engaging, The Goodness Paradox offers a...
58 days ago
Complexity Digest wrote a new blog post titled Where Does a Shark’s Skin Get Its Pattern?
In 1952, well before developmental biologists spoke in terms of Hoxgenes and transcription factors, or even understood DNA’s structure, Alan Turing had an idea. The famed mathematician who hastened the end of World War II by cracking the Enigma code turned his mind to the natural world and devised an elegant mathematical model of pattern formation. His theory outlined how endless varieties of stripes, spots, and scales could emerge from the interaction of two simple, hypothetical chemical agents, or “morphogens.” Decades passed before biologists seriously considered that this mathematical...
58 days ago
Complexity Digest wrote a new blog post titled Taking census of physics
Over the past decades, the diversity of areas explored by physicists has exploded, encompassing new topics from biophysics and chemical physics to network science. However, it is unclear how these new subfields emerged from the traditional subject areas and how physicists explore them. To map out the evolution of physics subfields, here, we take an intellectual census of physics by studying physicists’ careers. We use a large-scale publication data set, identify the subfields of 135,877 physicists and quantify their heterogeneous birth, growth and migration patterns among research areas. We...
58 days ago
Complexity Digest wrote a new blog post titled Opinion Dynamics and Collective Decisions
We expect that democracy enables us to utilize collective intelligence such that our collective decisions build and enhance social welfare, and such that we accept their distributive and normative consequences. Collective decisions are produced by voting procedures which aggregate individual preferences and judgments. Before and after, individual preferences and judgments change as their underlying attitudes, values, and opinions change through discussion and deliberation. In large groups, these dynamics naturally go beyond the scope of the individual and consequently might show unexpected...
58 days ago
Complexity Digest wrote a new blog post titled Topological control of synchronization patterns: Trading symmetry for stability
Symmetries are ubiquitous in network systems and have profound impacts on the observable dynamics. At the most fundamental level, many synchronization patterns are induced by underlying network symmetry, and a high degree of symmetry is believed to enhance the stability of identical synchronization. Yet, here we show that the synchronizability of almost any symmetry cluster in a network of identical nodes can be enhanced precisely by breaking its structural symmetry. This counterintuitive effect holds for generic node dynamics and arbitrary network structure and is, moreover, robust against...
58 days ago
Complexity Digest wrote a new blog post titled Self-referential basis of undecidable dynamics: From the Liar paradox and the halting problem to the edge of chaos
In this paper we explore several fundamental relations between formal systems, algorithms, and dynamical systems, focussing on the roles of undecidability, universality, diagonalization, and self-reference in each of these computational frameworks. Some of these interconnections are well-known, while some are clarified in this study as a result of a fine-grained comparison between recursive formal systems, Turing machines, and Cellular Automata (CAs). In particular, we elaborate on the diagonalization argument applied to distributed computation carried out by CAs, illustrating the key...
58 days ago