Macro and Micro Dynamics of City Size Distributions: The Case of Israel

We study the distribution of sizes in the Israeli system of cities, using a rank-size representation of population distributions from 1950 to 2005. Based on a multiplicative model of proportionate growth, we develop a quantitative comparison relating the change in the rank-size curves to the change in the real data of Israeli cities during this period. At the level of macro dynamics, there is good agreement between the model and the real data. At the micro level, however, the model is less successful as the mean variation of the cities’ rank during the period studied is much larger in the model than in the real data. To illustrate this difference, we use the rankclock representation

MetroNet: A Metropolitan Simulation Model Based on Commuting Processes

Part 3: Short PapersInternational audienceThe aim of this work is to identify a set of fundamental rules that govern the interactions within urban systems at the metropolitan scale. For that, we developed an USM (Urban Simulation Model) specifically designed to study the evolution and dynamics of systems of cities. Our model is innovative in its structure: it is a superposition of cellular automata and agent based modeling approaches (that are essentially spatial analyses) and a complex network approach (that is essentially a topological analysis). This implies that in our model, the local activities and interaction of agents give rise to the global urban structure and network that in turn affects the agents’ cognition, behavior, movement and action in the city and so on in circular causality. The model simulates commuting patterns of agents within a metropolis. The agents in our model represent workers who look for working places, the nodes represent urban employment centers, and the links represent commuters. Our results address three issues: the first suggests that the perception of urban boundaries plays a significant role in the metropolitan evolution in terms of network topology. This means that the existence of business centers, located in proximity to each other (but belonging to different municipalities) may lead to the emergence of new centers at the metropolis scale. The second issue concerns urban segregation; our results suggest that the location preferences of the agents regarding proximity to similar/different agents have a major affect not only on the urban morphology but also on the topology of the urban network. The third and last issue concerns the size distributions of agents in our model; these distributions correspond to all types of homogenous distributions observed in real system of cities

The end of a paradigm: is Zipf’s law universal?

Zipf’s law, City size distribution, Urbanization process, C, R,

Analyzing the Maritime Transportation System in Greece: a Complex Network Approach

Maritime networks of coastal and insular countries constitute fundamental transportation systems affecting the economy and the developmental dynamics of their countries. Under this perspective, the present article studies the Greek Maritime transportation Network (GMN), by using a complex network approach for the part of structural analysis and empirical techniques for the socioeconomic evaluation of the GMN’s topology. A methodological framework is developed for dealing with the GMN’s disconnectivity, which is evaluated by the empirical analysis. The curve fitting procedure on the degree distribution data indicated the existence of some scale-free network properties of the GMN, which seemed to be also captured as high correlations between pairs of binary and their homologous distance-weighted node structural variables, electing a topic of further empirical research on various networks. This status implies a kind of GMN’s structural indifference to distance, favoring the development of transportation activities into greater distances within the GMN. Also, the linear regression analysis modeled the connectivity of the GMN, electing topological, spatial and socioeconomic information. Finally, this paper elected the utility of complex network analysis in the study of national maritime networks, capable in providing new insights to the transportation policy makers of Greece. © 2014 Springer Science+Business Media New Yor