Core-periphery Structure Research Articles (Page 5)

This study aimed to examine the hidden structures and patterns among Chinese-language library and information science (CLIS) journals in Taiwan according to structural equivalence of social network analysis. Thirteen CLIS journals and 3,150 articles published between 2001 and 2014 were selected as subject and a 13x13 matrix was aggregated for structural equivalence analysis. The matrix was reduced into 6x6 blocks, and their block matrices and image diagrams were created based on results of structural equivalence analysis. The six blocks (i.e., general LIS I and II, core LIS I and II, interdisciplinary and residual) were used to examine the journal positions, network images and core-peripheral structure in the network. The block structure of the CLIS journal network shows both stability and change through the two individual periods of seven years (i.e., 2001-2007 and 2008-2014). The structural equivalence based results provide valuable alternative publication outlets for paper re-submission for scholars when a paper has been rejected. Such result is useful for journal editors to gain an image of which journals are competitive rivals in terms of journal-to-journal citation network. The core-periphery structure is roughly supported by this study both for the overall fourteen years and during two individual periods.

Rapid urbanization in China not only promotes the rapid expansion of urban population and economic agglomeration, but also causes the aggravation of haze pollution. In order to better clarify the asymmetric and nonlinear effects of urban scale and agglomeration on haze pollution, this paper quantitatively evaluates the spatial spillover effects of population size and economic agglomeration on haze pollution in 342 Chinese cities from 2001 to 2016 by using exploratory spatial data analysis (ESDA) and spatial econometric model. The results show the following: (1) During the research period, the distribution of urban scale, agglomeration, and haze pollution in China presented complex asymmetrical features, with the former two presenting a “core–periphery” distribution mode, while the latter having a tendency to spread around. In addition, under the influence of urban population size and economic agglomeration, haze pollution in Chinese cities presents significant spatial autocorrelation, with the agglomeration degrees showing a fluctuating upward trend during the study period. (2) Both urban scale and urban agglomeration have positive global spatiotemporal correlation with haze pollution. Local spatial correlation features are more obvious in China’s emerging urban agglomerations like Beijing–Tianjin–Hebei and Yangtze River Delta. (3) The spatial effects of haze pollution are better evaluated by spatial Durbin model (SDM) with spatial fixed effects, obtaining a coefficient of 0.416, indicating haze in neighboring cities affected each other and had significant spillover. By decomposing the effect of urban scale and agglomeration on haze as direct and indirect effects, the direct effect of urban population size and the indirect effect of urban economic agglomeration are found to be more prominent, reflecting that significant asymmetrical characteristics exist in the spatial effects of urban size and agglomeration on urban haze. (4) Among the control variables that affect China’s rapid urbanization, the level of urban economic development has a positive effect on haze pollution, while the high-level industrial structure and improved technical level can effectively reduce haze pollution. Continuous decline of haze concentration of Chinese cities in recent years has been indicating the spatial relationships between haze and urban size and agglomeration have a decoupling trend. The findings contribute to theory by emphasizing the spillover effect and spatial heterogeneities of geographical factors, and have implications for policy makers to deal with haze pollution reasonably and effectively.

Racial and Ethnic Diversity in the Urban Core and Suburban Periphery of Large Urban Areas in the U,S., 1980-2010

Recently, one type of mesoscale structure called core-periphery (CP) structure has received much attention in complex networks, as the algorithmic detection of such structures makes it possible to discover network features that are not apparent either at the local scale of nodes and edges or at the global scale of summary statistics. The core-periphery structure refers to that core nodes are densely interconnected, while periphery nodes are connected to core nodes to different extents, and periphery nodes are sparsely interconnected. Core-periphery structure containing a single core or multiple cores has been identified in various networks. However, investigation of the detection problems of the core-periphery has not been summarized in the literature. In this paper, we first introduce the definition of the core-periphery structure. The core-periphery structure has been paid more and more attention by researchers in various fields since its introduction, and it has been proved to be a powerful tool to analyze the theory of various topologies in our society, we briefly expounded the application of core-periphery structure in economics, sociology, medicine and other fields, and revealed the huge development potential of this theory. Then, we give a detailed overview of classical detection algorithms since the core-periphery structure theory was proposed. Finally, we give the development characteristics and the possible research directions of the core-periphery detection algorithm.

Core–periphery organization of the cryptocurrency market inferred by the modularity operator

Abstract Design innovation projects often generate large numbers of design ideas from designers, users, and, increasingly, the crowd over the Internet. Such idea data are often used for selection and implementation but, in fact, can 1also be used as sources of inspiration for further idea generation. In particular, the elementary concepts that underlie the original ideas can be recombined to generate new ideas. But it is not a trivial task to retrieve concepts from raw lists of ideas and data sources in a manner that can stimulate or generate new ideas. A significant difficulty lies in the fact that idea data are often expressed in unstructured natural languages. This paper develops a methodology that uses natural language processing to extract key words as elementary concepts embedded in massive idea descriptions and represents the elementary concept space in a core–periphery structure to direct the recombination of elementary concepts into new ideas. We apply the methodology to mine and represent the concept space underlying massive crowdsourced ideas and use it to generate new ideas for future transportation system designs in a real public sector-sponsored project via humans and automated computer programs. Our analysis of the human and computer recombination processes and outcomes sheds light on future research directions for artificial intelligence in design ideation.

At rest, human brain functional networks display striking modular architecture in which coherent clusters of brain regions are activated. The modular account of brain function is pervasive, reliable, and reproducible. Yet, a complementary perspective posits a core–periphery or rich-club account of brain function, where hubs are densely interconnected with one another, allowing for integrative processing. Unifying these two perspectives has remained difficult due to the fact that the methodological tools to identify modules are entirely distinct from the methodological tools to identify core–periphery structure. Here, we leverage a recently-developed model-based approach—the weighted stochastic block model—that simultaneously uncovers modular and core–periphery structure, and we apply it to functional magnetic resonance imaging data acquired at rest in 872 youth of the Philadelphia Neurodevelopmental Cohort. We demonstrate that functional brain networks display rich mesoscale organization beyond that sought by modularity maximization techniques. Moreover, we show that this mesoscale organization changes appreciably over the course of neurodevelopment, and that individual differences in this organization predict individual differences in cognition more accurately than module organization alone. Broadly, our study provides a unified assessment of modular and core–periphery structure in functional brain networks, offering novel insights into their development and implications for behavior.

This article argues that focusing on intra-European inequalities is key to a deeper understanding of the Brexit process, as the impacts of the Brexit process on core–periphery inequalities within Europe and on intra-European migrations remain under-researched topics. Focusing on sociology, this article provides a critical analysis of the burgeoning literature on Brexit, highlighting the centrality of methodological nationalism and its critique by critical race scholars. We expand the latter’s critique, providing a different solution to the national framing of the debate. Drawing on world-system theory and post-Bourdieusian social theory, we explore the role that Britain played in legitimising core–periphery inequalities in Europe and social hierarchies between West and East, and North and South, European populations. We highlight the UK’s influence over EU supranational policies and its association, among non-UK EU citizens, with a ‘meritocracy narrative’ that shapes patterns and meanings of intra-European migration. We further explore how inequalities of nation, class, race and gender make EU citizens unequally positioned to access the promises of this narrative. Overall, the article argues that a focus on intra-European inequalities is essential to an understanding of how Britain contributed to the unequal Europe it aims to leave, and how EU citizens’ unequal migrations make Brexit an asymmetrical process.

Abstract Textual idea data from online crowdsourcing contains rich information of the concepts that underlie the original ideas and can be recombined to generate new ideas. But representing such information in a way that can stimulate new ideas is not a trivial task, because crowdsourced data are often vast and in unstructured natural languages. This paper introduces a method that uses natural language processing to summarize a massive number of idea descriptions and represents the underlying concept space as word clouds with a core-periphery structure to inspire recombinations of such concepts into new ideas. We report the use of this method in a real public-sector-sponsored project to explore ideas for future transportation system design. Word clouds that represent the concept space underlying original crowdsourced ideas are used as ideation aids and stimulate many new ideas with varied novelty, usefulness and feasibility. The new ideas suggest that the proposed method helps expand the idea space. Our analysis of these ideas and a survey with the designers who generated them shed light on how people perceive and use the word clouds as ideation aids and suggest future research directions.

Relationships in the interbank market

The global automotive industry has been exposed to an overproduction crisis for several decades. Under the pressure of restructuring, automotive companies renew both the geographical scope and the technological standardization of their production processes. We analyze the effects this restructuring had on the development of European economies in order to understand whether vertical specializations in the automotive value chain can lead to Central and Eastern European countries’ catching up to advanced economies, or whether such specializations reproduce new forms of core-periphery relations. In order to answer this question, we introduce a new methodological approach to understand vertical specialization in the global value chain from a semi-peripheral perspective. We combine the theory of global value chains with Vernon's product life-cycle theory. In the research we focus on the standardization of the production of electric engines behind the geographical relocation of production between core and periphery.

The core-periphery structure of the Japanese lexicon is well documented (e.g., Ito & Mester 1995ab, 1999), but there is some controversy as to whether it is synchronically productive. Productive core-periphery structure should show synchronic evidence for a HIERARCHY OF FOREIGNNESS (Kiparsky 1973) among non-native phonological structures, and should give rise to IMPOSSIBLE-NATIVIZATION EFFECTS (Ito & Mester 1999, 2001)--speakers should reject a nonce loanword that nativizes a 'less-foreign' structure while preserving a 'more-foreign' one. We carried out an experiment to collect nonce-loan nativization judgments from speakers of Japanese in order to test these claims. We found, first, that participants have a hierarchy of foreignness that is approximately like the predicted one, but differs in the relative markedness of singleton [p] and sequences of nasal+voiceless obstruent; we also found some interspeaker variation in the hierarchy. Second, while most participants showed nativization preferences that look like impossible- nativization effects, not all participants had a consistent hierarchy of preferences across all constraint pairs. These results have implications both for the phonological analysis of existing stratum-specific alternations in Japanese and for theoretical approaches to loanword phonology.

G. Celi, A. Ginzburg, D. Guarascio, A. Simonazzi, Crisis in the European Monetary Union. A Core-Periphery Perspective

Delayed gamma determination at the JSI TRIGA reactor by synchronous measurements with fission and ionization chambers

Abstract With origins in post-war development thinking, the core–periphery concept has spread across the social and, increasingly, the natural sciences. Initially reflecting divergent socioeconomic properties of geographical regions, its relational connotations rapidly led to more topological interpretations. In today's network science, the standard core–periphery model consists of a cohesive set of core actors and a peripheral set of internally disconnected actors. Exploring the classical core–periphery literature, this paper finds conceptual support for the characteristic intra-categorical density differential. However, this literature also lends support to the notions of peripheral dependency and core dominance, power-relational aspects that existing approaches do not capture. To capture such power-relations, this paper suggests extensions to the correlation-based core–periphery metric of Borgatti and Everett (2000). Capturing peripheral dependency and, optionally, core dominance, these extensions allow for either measuring the degree of such power-relational features in given core–periphery partitions, or as part of a criteria function to search for power-relational core–periphery structures. Applied to the binary and valued citation data in Borgatti and Everett (2000), the proposed extensions seemingly capture dependency and dominance features of core–periphery structures. This is particularly evident when, circling back to the original domains of the concept, examining the network of European commodity trade in 2010.

What is the core of the human brain is a fundamental question that has been mainly addressed by studying the anatomical connections between differently specialized areas, thus neglecting the possible contributions from their functional interactions. While many methods are available to identify the core of a network when connections between nodes are all of the same type, a principled approach to define the core when multiple types of connectivity are allowed is still lacking. Here, we introduce a general framework to define and extract the core-periphery structure of multi-layer networks by explicitly taking into account the connectivity patterns at each layer. We first validate our algorithm on synthetic networks of different size and density, and with tunable overlap between the cores at different layers. We then use our method to merge information from structural and functional brain networks, obtaining in this way an integrated description of the core of the human connectome. Results confirm the role of the main known cortical and subcortical hubs, but also suggest the presence of new areas in the sensori-motor cortex that are crucial for intrinsic brain functioning. Taken together these findings provide fresh evidence on a fundamental question in modern neuroscience and offer new opportunities to explore the mesoscale properties of multimodal brain networks.

ABSTRACTThis paper focuses on analyzing the complexity level of the basket of parts and components exported by EU countries and how it is related to trade linked to international production networks. Three blocks of EU countries, which enjoy different available comparative advantages, are distinguished (Core, New Periphery, and Old Periphery). Our analysis shows that more than one third of exports of P&Cs are of very high complexity in the three blocks of countries. By estimating a panel data gravity model, we find that the higher the product complexity, the higher the volume of trade linked to international production networks, with the impact larger for EU Core countries that exhibit a wider set of high capabilities.

Abstract （399words） This paper aims to clarify and partially solve what tasks ongoing EMU has actually confronted since its establishment, mainly focusing on clarifying asymmetric transmission effects of an united Eurosystem’s monetary policy and on finding conditions of establishing value convergence among EMU and/or EU. Research design of this paper bases on both theoretical innovations （Control Engineering to achieve convergence） and empirically verifiable methods （Panel Fixed VARSARAR model: Panel Fixed Effects Vector AutoRegressive and Spatial AutoRegressive with Additional AutoRegressive Error Model）, which enables us to discuss EMU’s convergence tasks quantitatively. Accordingly, this paper consists of two parts. One is a verification part of EMU’s interrelated transmission effects of monetary policy, which clarifies how we can explain its asymmetric effects among EMU utilizing direct transmission and spatial indirect effects. Asymmetric effects of an united monetary policy have stemmed from idiosyncrasy of economic structures, spatial spillovers of its economic policy and human-made institutional spatial customs governing EMU and Euro among within and occasionally without EMU member states. This paper verifies whether inclusive theory of monetary policy explains variations of real and interrelated EMU’s convergent criterion indicators by which monetary channels have affected HICP and fiscal resilience by such as Quantitative Easing and Fiscal Theory of the Price Level （FTPL） channels. The other is a part of establishment conditions of multibody-made convergence system through control by human utilizing methods of Control Engineering or state-space model, which enables us to lead EMU from divergence toward convergence of European values. This paper also discusses how to procced EMU’s policy convergence by human-made innovations through diagonalization of both direct and indirect matrix through introduction of single-peakedness or stratification of national priority issues among EMU members or Euro, which means that EMU’s or EU’s convergence of values needs some form of stratification without fail. The results of this paper are as follows: VARSARAR model implies that indirect spatial lags which seem to represent crisis-driven fragility and distance-based neglectedness as core-periphery structures within the EU, and among-countries-linked financial contagion in Europe that are possibly but not completely verified as background reasons of distance-based European spatial lags, have actually large effects on inflation and fiscal position during crisis, and have also less effects on them after mitigation of the European crisis. Also, Control Engineering implies that One Europe necessarily requires stratification of member states’ sovereignty or euro in order to proceed and establish convergence of European view of values, say EMU and Euro.

This paper discusses three basic ways in which loanwords pattern differently than native vocabulary, with a particular focus on the implicational relationships that hold among generalizations that apply at different degrees of nativization. We argue that the overall typology and the effects of the core-periphery structure are best modeled if constraints are weighted as in Harmonic Grammar (Legendre, Miyata & Smolensky 1990), and violation scores are scaled according to degree of nativization. The implicational patterns of repair versus non-repair are predicted from basic patterns of interaction among scalar constraints, obviating the need for the kinds of ranking metaconditions required in ranked-constraint alternatives.

In the heterogeneous minor actinides transmutation approach, the nuclei to be transmuted are loaded in dedicated targets often located at the core periphery, so that long-lived heavy nuclides are turned into shorter-lived fission products by fission. To compensate for low flux level at the core periphery, the minor actinides content in the targets is set relatively high (around 20 at.%), which has a negative impact on the reprocessing of the targets due to their important decay heat level. After a complete analysis of the main contributors to the heat load of the irradiated targets, it is shown here that the choice of the reprocessing order of the various feeds of americium from the fuel cycle depends on the actual limit for fuel reprocessing. If reprocessing of hot targets is possible, it is more interesting to reprocess first the americium feed with a high243Am content in order to limit the total cooling time of the targets, while if reprocessing of targets is limited by their decay heat, it is more interesting to wait for an increase in the241Am content before loading the americium in the core. An optimization of the reprocessing order appears to lead to a decrease of the total cooling time by 15 years compared to a situation where all the americium feeds are mixed together when two feeds from SFR are considered with a high reprocessing limit.