The imprint of tourism on the topology of maritime networks: evidence from Greece

This paper examines the tourism information enclosed in the topology of the Greek maritime network (GMN) referring to a coastal country with many islands and a tourism orientation in its economy. The rationale of the analysis concerns the symbiotic relationship between tourism and transportation, which under the network paradigm defines the triplet of tourism–transportation network–economy, suggesting the criterion of the grouping of the available variables. The results verify the interacting role between these components for economic development, illustrate a gravity structure in the GMN, and validate the utility of network analysis in socioeconomic research. Overall, this article introduces network topology as a new variable in the study of tourism and transportation systems. © 2016 Informa UK Limited, trading as Taylor & Francis Group

Links between network topology and socioeconomic framework of railway transport: Evidence from Greece

This paper studies the Greek railway network (GRAN) by using complex network analysis (CNA) and empirical approach. The study aims to detect the socioeconomic information immanent to the GRAN's topology and to provide insights about how this network serves regional development. The analysis shows that the GRAN's topology complies with the empirical findings on railway networks, which are described by lattice-like characteristics, due to intense spatial constraints, but it outperforms the topology of a lattice and resembles more to a bus-like configuration. The major conclusion, in terms of regional policy, concerns that the GRAN enjoys an effective architecture of bus-topology, but its socioeconomic functionality is not as effective as its topology. Overall, the analysis provides evidence for the utility of applying the network paradigm to transportation research, regional, and spatial studies. © 2017 Eastern Macedonia and Thrace Institute of Technology

Detecting different topologies immanent in scale-free networks with the same degree distribution

The scale-free (SF) property is a major concept in complex networks, and it is based on the definition that an SF network has a degree distribution that follows a power-law (PL) pattern. This paper highlights that not all networks with a PL degree distribution arise through a Barabási−Albert (BA) preferential attachment growth process, a fact that, although evident from the literature, is often overlooked by many researchers. For this purpose, it is demonstrated, with simulations, that established measures of network topology do not suffice to distinguish between BA networks and other (random-like and lattice-like) SF networks with the same degree distribution. Additionally, it is examined whether an existing self-similarity metric proposed for the definition of the SF property is also capable of distinguishing different SF topologies with the same degree distribution. To contribute to this discrimination, this paper introduces a spectral metric, which is shown to be more capable of distinguishing between different SF topologies with the same degree distribution, in comparison with the existing metrics. © 2019 National Academy of Sciences. All Rights Reserved

Detecting differences in the topology of scale-free networks grown under time-dynamic topological fitness

The fitness model was introduced in the literature to expand the Barabasi-Albert model’s generative mechanism, which produces scale-free networks under the control of degree. However, the fitness model has not yet been studied in a comprehensive context because most models are built on invariant fitness as the network grows and time-dynamics mainly concern new nodes joining the network. This mainly static consideration restricts fitness in generating scale-free networks only when the underlying fitness distribution is power-law, a fact which makes the hybrid fitness models based on degree-driven preferential attachment to remain the most attractive models in the literature. This paper advances the time-dynamic conceptualization of fitness, by studying scale-free networks generated under topological fitness that changes as the network grows, where the fitness is controlled by degree, clustering coefficient, betweenness, closeness, and eigenvector centrality. The analysis shows that growth under time-dynamic topological fitness is indifferent to the underlying fitness distribution and that different topological fitness generates networks of different topological attributes, ranging from a mesh-like to a superstar-like pattern. The results also show that networks grown under the control of betweenness centrality outperform the other networks in scale-freeness and the majority of the other topological attributes. Overall, this paper contributes to broadening the conceptualization of fitness to a more time-dynamic context. © 2020, The Author(s)

City-size or rank-size distribution? An empirical analysis on Greek urban populations

This paper examines the utility of size distribution analysis in the study of urban systems, comparing two of the most popular versions, the rank-size (RSD) and the city-size distribution (CSD). These versions are compared in accordance to their capability to illustrate patterns of hierarchy in urban systems and to include coherent socioeconomic information when decomposed into multivariate regression variables. The research questions are examined empirically on data of the 2011 Greek national census. Overall, this study concludes that size-distribution analysis is useful in the study of urban systems, is capable in illustrating patterns of hierarchy, and it contains socioeconomic information, whereas the RSD and CSD share complementary roles and should be used jointly in relevant approaches. © 2016, Research Centre in Public Administration and Public Services,cademy of Economic Studies, Bucharest, Romania. All rights reserved

Determining the Driving Factors of Commuting: An Empirical Analysis from Greece

Commuting refers to the act of daily traveling, between two locations, for employment purposes and suggests a multidimensional phenomenon in Regional Science, which is determined by social, economic, geographic and political factors. This paper conducts initially a literal approach of the phenomenon and further proceeds to an empirical ordinal regression analysis for the spatial network consisting of two Greece regions (Thessaly and Sterea Hellas) that verifies the theoretical framework. The theoretical review contributes to the formulation of the independent (predictor) variables and generally to the construction of the ordinal regression model and the corresponding empirical approach, in order to specialize the theoretical framework to the Greek case and to recognize the spatial patterns that rule the commuting phenomenon. Some conclusions that are made, come to an agreement with the well established theories of gravity modeling, expanding city and binomial law and others elect an amount of interesting contradictions to the theoretical framework

Introducing an inequalities index from the simple perceptron pattern in ANN: An unemployment inequalities application in regional economics

This article introduces a new inequalities index, which was inspired from the simple perceptron's pattern in the artificial neural networks (ANN) scientific field and nominated by the authors Modulus Perceptron Inequalities Index (MPII). The structural similarities of this ANN pattern with a binary logic gate, in the Digital Electronics Theory (DET), lead to deal with the existence of operational similarities between these two models. The introduced index aroused while examining the potentials of the simple perceptron to solve the non-linear separable "exclusive disjunction" (XOR) problem, by using techniques of the Theory of Numbers in Mathematics. Since the XOR architecture is considered by the DET an inequality detector, due to its ability to result to the same outcome in the same input values, the solution of the XOR problem for a simple perceptron authorizes the ANN and DET XOR models to be considered identical, in the extend that inequalities is regarded. The above XOR models utility appears to operate satisfactory in Regional Science's inequalities research. The examination of MPII's behavior in comparison with the Theil index, concluded to be almost identical in the extend that slope conservation is regarded and more capable on cases that the Theil's index cannot operate. © 2012 Kavala Institute of Technology

Assessing the tourism performance of the Mediterranean coastal destinations: A combined efficiency and effectiveness approach

This paper assesses the comparative performance of the Mediterranean coastal destinations using data envelopment analysis, considering both the efficiency and effectiveness dimensions. The analysis does not only provide a benchmarking framework for the destinations, but a framework to reveal, in a comparative context, the trade-offs between efficiency and effectiveness, the sources of inefficiency, and the pillars of effectiveness, for each region. This paper advances the current literature in destination performance benchmarking, under the production frontier method, by incorporating the effectiveness dimension to the broadly used efficiency consideration. This advancement is of critical importance, considering that the results of this paper support the lack of a strong relationship between destinations' efficiency and effectiveness. Therefore, individual destinations' assessments, based only on one of the two performance dimensions, may lead to biased estimations that may mislead policy interventions. © 2019 Elsevier Lt

Ultrasonographic diagnosis of carpal tunnel syndrome: introducing a new approach

Introduction: CTS, the most common nerve entrapment syndrome of the upper limb, is being diagnosed by clinical criteria, in most cases supported by the electrodiagnosis method, which appears limits regarding its sensitivity and specificity and suggests an intervening and expensive technique. The purpose of this study was to contribute to establishing U/S examination as a method with at least of the same accuracy with electrodiagnosis. Material and method: A sample of 60 healthy individuals and 30 patients suffering from CTS was scanned. The diagnosis was conducted by both clinical and electrodiagnostic criteria, or by clinical criteria supported by postsurgical outcome. Method: In order to improve the accuracy of measurements, the anteroposterior to transverse diameter of the median nerve inside the canal and in its entrance was scanned and compared, by sonography. The examination conducted three times for each dimension, and the mean value per individual was calculated. Results: The mean ratios for the 60 healthy wrists was found to range within the interval 0.49–0.88 (presenting a mean value of 0.66), and the corresponding for the 30 suffering from CTS wrists was within the interval 1.12–1.59 (with a mean value of 1.39). Conclusion: The statistical analysis of the examination results clearly demonstrates that the interval of ratios over the value 1.07 can be considered completely safe to diagnose that someone is suffering from CTS. In correspondence, a U/S measurement of ratios in the area up to 0.79 is completely safe to opine that this wrist refers to a healthy individual. The intermediate range of ratios 0.79–1.0 suggests a grey zone, which, by the rational of this study, does not include discrete CTS or healthy cases. This “gap” may describe subclinical or mild cases of CTS which were not been taken under consideration and for which there is no rational to interfere surgically. In the everyday’s practice clinical point of view, the grey zone cases are considered healthy. © 2015, Springer-Verlag France

Making the Web-Science Operational for Interregional Commuting Analysis: Evidence from Greece

This article proposes a Network Theoretical model for the interregional commuting analysis, estimating the volume of commuters that operate in a commuting network, based on the conceptual framework of the term “Web,” as provided by the Web-Science. Initially, the Web-Science’s conceptual framework is being generalized to operate for any kind of network and, afterwards, the proposed model is constructed, under the rationale that each conceptual component in the generalized Network Theoretical framework should be represented by different variables. The applicability of the proposed model is evaluated on real data of the Greek interregional commuting system, formulated by the capital cities of the Greek non-insular prefectures (|V(G)| = 39) and by their respective interconnection axes (|E(G)| = 72). The results of the analysis show respect to the categories of the proposed conceptual framework, where the overall empirical analysis of the Greek interregional commuting network elected the population variable as the most determinative factor for the commuting phenomenon. © 2015, Springer Science+Business Media New York