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Statistical mechanics of complex networks
 Rev. Mod. Phys
"... Complex networks describe a wide range of systems in nature and society, much quoted examples including the cell, a network of chemicals linked by chemical reactions, or the Internet, a network of routers and computers connected by physical links. While traditionally these systems were modeled as ra ..."
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Cited by 1188 (8 self)
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Complex networks describe a wide range of systems in nature and society, much quoted examples including the cell, a network of chemicals linked by chemical reactions, or the Internet, a network of routers and computers connected by physical links. While traditionally these systems were modeled as random graphs, it is increasingly recognized that the topology and evolution of real
Traffic and related selfdriven manyparticle systems
, 2000
"... Since the subject of traffic dynamics has captured the interest of physicists, many surprising effects have been revealed and explained. Some of the questions now understood are the following: Why are vehicles sometimes stopped by ‘‘phantom traffic jams’ ’ even though drivers all like to drive fast? ..."
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Cited by 146 (23 self)
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Since the subject of traffic dynamics has captured the interest of physicists, many surprising effects have been revealed and explained. Some of the questions now understood are the following: Why are vehicles sometimes stopped by ‘‘phantom traffic jams’ ’ even though drivers all like to drive fast? What are the mechanisms behind stopandgo traffic? Why are there several different kinds of congestion, and how are they related? Why do most traffic jams occur considerably before the road capacity is reached? Can a temporary reduction in the volume of traffic cause a lasting traffic jam? Under which conditions can speed limits speed up traffic? Why do pedestrians moving in opposite directions normally organize into lanes, while similar systems ‘‘freeze by heating’’? All of these questions have been answered by applying and extending methods from statistical physics and nonlinear dynamics to selfdriven manyparticle systems. This article considers the empirical data and then reviews the main approaches to modeling pedestrian and vehicle traffic. These include microscopic (particlebased), mesoscopic (gaskinetic), and macroscopic (fluiddynamic) models. Attention is also paid to the formulation of a micromacro link, to aspects of universality, and to other unifying concepts, such as a general modeling framework for selfdriven manyparticle systems, including spin systems. While the primary focus is upon vehicle and pedestrian traffic, applications to biological or socioeconomic systems such as bacterial colonies, flocks of birds, panics, and stock market dynamics are touched upon as well.
Counting lattice animals: a parallel attack
 Journal of Statistical Physics
, 1992
"... A parallel algorithm for the enumeration of isolated connected clusters on a regular lattice is presented. The algorithm has been implemented on 17 RISCbased workstations to calculate the perimeter polynomials for the plane triangular lattice up to clustersize s = 21. New data for perimeter polynomi ..."
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Cited by 5 (1 self)
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A parallel algorithm for the enumeration of isolated connected clusters on a regular lattice is presented. The algorithm has been implemented on 17 RISCbased workstations to calculate the perimeter polynomials for the plane triangular lattice up to clustersize s = 21. New data for perimeter polynomials D s up to D21, total number of clusters gs up to g22, and coefficients b ~ in the lowdensity series expansion of the mean cluster size up to b21 are given.
Measures of critical exponents in the fourdimensional site percolation
"... Using finitesize scaling methods we measure the thermal and magnetic exponents of the site percolation in four dimensions, obtaining a value for the anomalous dimension very different from the results found in the literature. We also obtain the leading correctionstoscaling exponent and, with great ..."
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Cited by 5 (0 self)
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Using finitesize scaling methods we measure the thermal and magnetic exponents of the site percolation in four dimensions, obtaining a value for the anomalous dimension very different from the results found in the literature. We also obtain the leading correctionstoscaling exponent and, with great accuracy, the critical density.
Lattice animals: A fast enumeration algorithm and new perimeter polynomials
 J. Stat. Phys
, 1990
"... A fast computer algorithm for enumerating isolated connected clusters on a regular lattice and its Fortran implementation are presented. New perimeter polynomials are calculated for the square, the triangular, the simple cubic, and the square lattice with next nearest neighbors. KEY WORDS: Cluster e ..."
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Cited by 4 (1 self)
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A fast computer algorithm for enumerating isolated connected clusters on a regular lattice and its Fortran implementation are presented. New perimeter polynomials are calculated for the square, the triangular, the simple cubic, and the square lattice with next nearest neighbors. KEY WORDS: Cluster enumeration; Fortran program; perimeter polynomials. 1.
MITCTP3331 From boom to bust and back again: the complex dynamics of trends and fashions
, 2008
"... Social trends or fashions are spontaneous collective decisions made by large portions of a community, often without an apparent good reason. The spontaneous formation of trends provides a well documented mechanism for the spread of information across a population, the creation of culture and the sel ..."
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Cited by 2 (1 self)
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Social trends or fashions are spontaneous collective decisions made by large portions of a community, often without an apparent good reason. The spontaneous formation of trends provides a well documented mechanism for the spread of information across a population, the creation of culture and the selfregulation of social behavior. Here I introduce an agent based dynamical model that captures the essence of trend formation and collapse. The resulting population dynamics alternates states of great diversity (large configurational entropy) with the dominance by a few trends. This behavior displays a kind of selforganized criticality, measurable through cumulants analogous to those used to study percolation. I also analyze the robustness of trend dynamics subject to external influences, such as population growth or contraction and in the presence of explicit information biases. The resulting population response gives insights about the fragility of public opinion in specific circumstances and suggests how it may be driven to produce social consensus or dissonance.
Lattice animals and the Percolation model under rotational constraint
, 1997
"... The effect of rotational constraint on the properties of lattice models like the selfavoiding walk, lattice animals and percolation is discussed. The results obtained so far, using a variety of exact and approximate techniques, are described. Examples of the rotational constraint in real systems ar ..."
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Cited by 1 (0 self)
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The effect of rotational constraint on the properties of lattice models like the selfavoiding walk, lattice animals and percolation is discussed. The results obtained so far, using a variety of exact and approximate techniques, are described. Examples of the rotational constraint in real systems are also given. I.
Structure and Relaxation Dynamics of a Colloidal Gel
, 2006
"... Abstract. – Using molecular dynamics computer simulations we investigate the structural and dynamical properties of a simple model for a colloidal gel at low volume fraction. We find that at low T the system is forming an open percolating cluster, without any sign of a phase separation. The nature o ..."
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Abstract. – Using molecular dynamics computer simulations we investigate the structural and dynamical properties of a simple model for a colloidal gel at low volume fraction. We find that at low T the system is forming an open percolating cluster, without any sign of a phase separation. The nature of the relaxation dynamics strongly depends on the length scale/wavevector considered and can be directly related to the geometrical properties of the spanning cluster. Gels are ubiquitous in daily life, biology, as well as technological applications. Like glassforming systems, they are disordered and have slow and nontrivial relaxation [1,2]. On the other hand, they are characterized by open spanning structures [3] and hence have a volume fraction φ that is significantly smaller than unity. To what extent the structural properties are related to the dynamical properties and what mechanism is responsible for the complex dynamics of these systems, are important questions to which so far no clear answer has been given. In particular, in view of the different nature of the various gels (colloidal gels, chemical gels, etc.), it is not evident at all that there are indeed unique answers. In view of this variety it is not surprising that in the past various mechanisms for the complex
Review Piezoresistive Strain Sensors Made from Carbon Nanotubes Based Polymer Nanocomposites
, 2011
"... sensors ..."
FirstPassage Percolation, SemiDirected Bernoulli Percolation, and Failure in Brittle Materials
, 1997
"... We present a twodimensional, quasistatic model of fracture in disordered brittle materials that contains elements of firstpassage percolation, i.e., we use a minimumenergyconsumption criterion for the fracture path. The firstpassage model is employed in conjunction with a "semidirected " Berno ..."
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We present a twodimensional, quasistatic model of fracture in disordered brittle materials that contains elements of firstpassage percolation, i.e., we use a minimumenergyconsumption criterion for the fracture path. The firstpassage model is employed in conjunction with a "semidirected " Bernoulli percolation model, for which we calculate critical properties such as the correlation length exponent vsdir and the percolation threshold pcsdir. Among other results, our numerics suggest that vSdir is exactly 3/2, which lies between the corresponding known values in the literature for usual and directed Bernoulli percolation. We also find that the wellknown scaling relation between the "wandering " and energy fluctuation exponents breaks down in the vicinity of the threshold for semidirected percolation. For a restricted class of materials, we study the dependence of the fracture energy (toughness) on the width of the distribution of the specific fracture energy and find that it is quadratic in the width for small widths for two different random fields, suggesting that this dependence may be universal. KEY WORDS: brittle materials. Firstpassage percolation; semidirected percolation; fracture; 1.