core periphery structure Research Articles (Page 1)

Purpose This study examines the evolution of education research in Kazakhstan from 1992 to 2024, a period marked by profound transformation, aiming to assess how scholarly output aligns with national education policy and broader developmental priorities. Design/methodology/approach A mixed bibliometric and natural language processing (NLP) approach was employed to analyze 956 English-language publications indexed in the Web of Science. The study combined quantitative analyses of publication trends, authorship and institutional collaboration with NLP techniques, including keyword co-occurrence, topic modeling and sentiment analysis, framed by a review of Kazakhstan’s education policy phases: post-Soviet foundational reforms and an era of global alignment. Findings Results reveal a substantial surge in research output, particularly after 2020, driven by a core set of highly productive authors and institutions. Thematic analyses indicate partial alignment with policy priorities, with multilingual education, digitalization and pedagogical innovation prominent, while inclusive education and social justice appear less substantively addressed. Collaboration networks display a core-periphery structure, with Nazarbayev University acting as the primary international and national hub. Originality/value This study offers the first comprehensive, longitudinal mapping of Kazakhstani education research, integrating bibliometric and NLP methods with policy analysis. It highlights both the rapid quantitative growth and the structural and thematic limitations of the field, providing a foundation for policy and institutional strategies aimed at fostering more diverse, critical and sustainable research.

Background/Objectives: This study investigates the interaction and coordinated development of the digital economy and the tourism economy in China’s Yangtze River Delta urban agglomeration, using panel data from 27 cities covering the period from 2013 to 2022. Methods: Composite indices are constructed for the two subsystems, with indicator weights determined using the entropy method. A coupling coordination model is then applied to assess the extent and quality of their joint development. Exploratory spatial data analysis is further employed to examine spatial dependence and clustering patterns, with Moran’s I serving as a key analytical measure. Results: The findings indicate that both subsystems improved over the study period, although the digital economy advanced more quickly and showed greater regional disparity. The overall coordination level rose from a medium stage to a relatively high stage, yet uneven development persisted, particularly in Anhui. Spatially, coordination followed an east-high, west-low pattern, and high-level areas gradually spread outward from leading cities to form a core–periphery structure. Positive spatial clustering was evident in most years, pointing to clear regional agglomeration in digital–tourism coordination. Conclusions: These results underscore the importance of differentiated regional policies, stronger inter-city collaboration, and deeper integration between digital development and tourism transformation.

Intergovernmental organizations (IGOs) attempt to shape global policy through scientific guidelines and assessments. While they rely on external scientists to bridge research and IGO advisory processes, the structural pathways connecting science to IGO documents remain unexamined. By linking 230,737 scientific papers referenced in IGO documents (2015-2023) to their authors and coauthorship networks across 23 research fields, we identified a small cohort of "Highly IGO-Cited Scientists" (HIC-Sci)-typically comprising 0.7% to 4.4% of authors whose work accounts for 30% of IGO-cited papers. This structural concentration is associated with relational and cognitive patterns: dense transnational collaboration networks, overlapping memberships on advisory bodies such as the Intergovernmental Panel on Climate Change, rapid uptake in IGO documents, and standardized policy-oriented vocabularies. Geographically, HIC-Sci networks follow a core-periphery structure centered on Western Europe. Established fields, such as climate modeling, show stronger concentration, whereas emerging domains such as data science & AI show more distributed citation patterns. Major IGOs frequently cocite the same HIC-Sci papers, compounding this concentration through synchronized diffusion across IGOs. This concentration persists despite IGOs' efforts to broaden participation and diversify their evidence base. While IGOs have developed criteria for selecting knowledge in advance, our framework provides a basis for subsequent assessment of how IGOs' efforts to influence policy rely on a concentrated set of HIC-Sci.

Fine-scale accounting of land use carbon budgets and identification of their driving factors provides an essential scientific basis for constructing green and low-carbon territorial spatial systems. This is of great significance for optimizing territorial spatial structure and promoting low-carbon development in urban agglomerations. Taking the Central Guizhou Urban Agglomeration as the study area, this study employed a composite carbon coefficient method to construct a 30 m × 30 m grid-based carbon budget index and quantitatively assessed carbon budget changes induced by land use transitions from 2000 to 2024. POI data and a quantile regression model were further integrated to analyze the dominant spatial characteristics associated with carbon budgets, and a carbon budget monitoring and early-warning index was developed to delineate risk zones. The results show that: (1) From 2000 to 2024, the total area of land use change reached 0.95 × 104 km2 in the Central Guizhou Urban Agglomeration, accounting for 17.68% of the total land area, and leading to a net increase of 2.3821 million tons of carbon emissions. This increase was primarily associated with the conversion of cultivated land to construction land, with an accelerated growth rate observed in the later period. (2) The spatial patterns of carbon budgets and carbon emission risk levels exhibit a distinct “core–periphery” structure, with high carbon emission levels concentrated in built-up urban areas and lower levels observed in peripheral ecological land. (3) The expansion of construction land is the dominant contributor to the increase in net carbon emissions; industrial, transportation, and residential spaces exert significant positive driving effects, whereas commercial and service spaces show a negative association. (4) Carbon budget risk zoning based on dominant spatial characteristics identifies Guiyang and Anshun as extremely high-risk areas. The results further suggest that reducing carbon-increment spaces and increasing carbon-reduction spaces may play an important role in territorial carbon budget optimization. The integrated “accounting–driving–monitoring” analytical framework established in this study provides a scientific basis for territorial spatial optimization and carbon emission reduction in mountainous urban agglomerations.

Global supply chains face increasing vulnerability to disruptions from geopolitical tensions, natural disasters, and demand shocks. The global trade network for railway vans, critical for transcontinental freight transport, remains understudied despite its foundational role in global logistics. This study addresses the gap in understanding how the railway vans trade network structure evolves and responds to different types of shocks, moving beyond static analyses to capture dynamic vulnerabilities. Using UN Comtrade data (2013-2024), multi-level network analysis examined structural evolution at macroscopic, mesoscopic, and microscopic scales. Three risk propagation models simulated supply disruption, demand shock, and cooperation disruption scenarios to assess systemic vulnerabilities. The network transformed from a polycentric to core-periphery structure, with China dominating exports (67 partners in 2024) and Germany leading European integration. Supply disruptions from Romania and Czechia affected up to 114 countries under low risk absorption capacity (α = 0.1), while demand shocks from the USA impacted 53 countries. The disruption of strategic trade links, such as China-Australia, triggered severe systemic risks. The systemic criticality of risk sources varies by shock type, requiring context-specific resilience strategies. The findings guide policymakers in identifying critical vulnerabilities and designing targeted interventions for enhancing supply chain resilience in infrastructure sectors.

Global urbanization has long been hampered by the “metrocentric priority” paradigm, with small towns—core hubs for urban–rural integration—severely undervalued in practical value. Amid China’s transition to high-quality urban–rural integration, unbalanced small town development has become a critical bottleneck for county-level factor flows, demanding systematic research to unlock their strategic value and resolve urban–rural dual predicaments. Existing studies suffer from scientific gaps including unidirectional linear cognition, insufficient complex system thinking, and weak interpretation of regional heterogeneity, remaining at the stage of static correlation description and failing to reveal the two-way reciprocal feedback logic between small towns and urban–rural integration. Meanwhile, the application of complex system theory in urban–rural research is still confined to theoretical narratives, which hinders the advancement of research from descriptive analysis to mechanism interpretation. Taking Henan Province (a typical agricultural and populous province reflecting China’s urban–rural development) as a case, this study builds a “local emergence–global synergy” framework based on complex system theory, establishes a dual indicator system for small towns’ multidimensional performance and county-level urban–rural integration, and integrates spatial statistical analysis, bidirectional regression and coupling coordination models to explore their cross-scale spatiotemporal evolution and reciprocal feedback during 2019–2023. Findings show the following: (1) The multidimensional performance of small towns presents a pattern characterized by polarized expansion of high-value regions and overall improvement of low-value regions, while county-level urban–rural integration evolves into a polycentric structure featured by central dominance and southern growth. (2) There is a significant two-way asymmetric relationship between small towns’ multidimensional performance and county-level urban–rural integration: the positive effect is significantly stronger than the reverse effect, and both direct impacts are significantly weakened after introducing economic variables, indicating that economic development serves as a key transmission channel. (3) The coupling mechanism presents three evolutionary paths with pronounced core–periphery spatial heterogeneity. Grounded in complex system theory, this study constructs a systemic analytical framework of “local emergence of small-town subsystems and global synergy of county-level systems”, verifies the core proposition of two-way interactions between subsystems and the overall system in the urban–rural complex giant system, and enriches the localized application of complex system theory and the urban–rural continuum theory in traditional agricultural regions of China. This study provides a foundational empirical paradigm for the in-depth exploration of nonlinear characteristics and threshold effects in future research. It offers theoretical support for policy formulation of county-level urban–rural integration in traditional agricultural regions of China, and it provides Chinese experiences for the Global South with similar contexts to explore inclusive urbanization pathways, promoting cross-cultural dialogue and practical transformation of urban–rural integration theory.

A novel approach for analyzing the structural integrity and operational vulnerability of complex networks using intuitionistic fuzzy graphs has been modeled. While traditional fuzzy graph metrics focus primarily on existence, they fail to capture the holistic systemic impact of failures. To overcome this limitation, a scalar-based measure of nodal importance that integrates both existence (membership degree) and non-existence (non-membership degree) values of incident edges into a single critical metric has been developed. The proposed indices demonstrate enhanced sensitivity to network perturbations compared to conventional degree centrality measures, capturing latent vulnerabilities in critical infrastructure topologies. Based on this, two indices are proposed: Intuitionistic Fuzzy Degree Index and Intuitionistic Edge Interaction Index. These indices quantify the total system activity, stress dispersion, overall network cohesiveness, and potential for cascading failure propagation. When applied to synthetic core-periphery networks, the proposed indices identified critical nodes with superior discrimination capability compared to existing fuzzy graph metrics, revealing that removal of identified nodes results in system-wide connectivity degradation observable through both membership and non-membership approximations. This methodology was applied to a core-periphery communication network to analyze the systemic consequences of node removal. Experimental validation on networks of varying sizes demonstrates that the Intuitionistic Edge Interaction Index achieves robust node criticality ranking across heterogeneous network topologies with improved predictive accuracy for cascade initiation points. This work provides network analysts and engineers a quantitative tool to precisely assess criticality and inform targeted resilience strategies in uncertain, high-risk environments.

Purpose This study applies social network analysis to examine how 572 UK farm businesses engage with eight marketing channels, aiming to understand how patterns of market access relate to structural position, business characteristics and resilience. Design/methodology/approach Measures of degree centrality, core–periphery structure and modularity clustering were used to uncover the relational architecture of the UK farms’ marketing channels. Findings Findings show that most farms rely on just one or two channels, with those using three or more exhibiting the highest network centrality. The findings highlight the need to distinguish between structural embeddedness and functional integration. A farm may be well connected yet remain marginal in terms of capital flow or market influence. Practical implications Policies aiming to strengthen food system resilience must be network-aware and support a plurality of marketing strategies tailored to different farm contexts enabling resilience and innovation to emerge across all parts of the network. Originality/value The findings presented herein offer practical recommendations for rural development and national procurement frameworks showing how structural positioning and connectivity can inform typologies for targeted and equitable intervention.

IntroductionPopulation ageing in Guangzhou has continued to intensify, and the older adult population is increasingly concentrated in central urban areas. This concentration amplifies spatial mismatch between service demand and resource allocation, thereby shaping both the equity of public service provision and the capacity of urban governance.MethodsUsing district-level data on older adult care service demand and care-service resources in Guangzhou from 2015 to 2023, we develop an integrated analytical framework combining the entropy-weight method, spatial autocorrelation analysis, geographic concentration measures, and inconsistency indices. This framework is applied to identify the spatial structure of demand–resource alignment and its evolution over time.ResultsThe analysis reveals a clear core–periphery pattern. Central urban districts form structural “bottleneck zones,” characterised by high service demand and insufficient resource supply. Peripheral districts, by contrast, display a reverse mismatch: comparatively higher pre-allocated resources alongside lagging or slower-growing demand. Transitional districts between the urban core and outer areas exhibit relatively better coordination between demand and resources.DiscussionOverall, Guangzhou’s older adult care system appears to be entering a phase of structural adjustment in which misalignment is driven less by absolute scarcity alone and more by spatial configuration and cross-district spillovers. Policy priorities should therefore shift toward spatial optimisation of facilities and service capacity, strengthened cross-district coordination mechanisms, and more targeted resource allocation that responds to the evolving geography of the older population and care needs.

Introduction Enhancing transportation accessibility is often viewed as a catalyst for rural revitalization, yet its compatibility with sustainable forestry remains a critical challenge. This study examines the impact of highway construction on rural forest resources in China’s underdeveloped regions. Methods Using town-level transportation and forestry data from 2009 to 2019, we exploit spatial variation in highway openings and implement a difference-in-differences (DID) framework. To address endogeneity concerns, we further employ an instrumental variable (IV) strategy based on hypothetical least-cost path spanning tree networks. Dynamic specifications and multiple validity checks are used to ensure causal interpretation. Results We find a significant negative spatial spillover effect of highway openings. Specifically, highways built in neighboring townships substantially reduce forest cover in townships that lack direct highway access, whereas the construction of non-highway roads has no statistically discernible effect. This adverse impact is transient and gradually attenuates over time. Mechanism analyses grounded in a core–periphery framework show that highways lower transportation costs and accelerate the outflow of timber and ecological capital from peripheral rural areas to central markets. Heterogeneity analyses indicate that forest loss is most pronounced near highway exits, in commercially valuable broadleaf forests, and in regions dominated by timber extraction and tourism but lacking institutional protection. Ecologically, highway-induced deforestation significantly increases greenhouse gas emissions by weakening carbon sinks, while effects on vehicle exhaust pollutants are negligible. Discussion Our findings highlight a trade-off between infrastructure-led connectivity and ecological sustainability. Achieving rural revitalization without exacerbating environmental degradation requires differentiated infrastructure investment and stronger ecological governance, particularly in peripheral rural areas vulnerable to market-driven deforestation.

Inequity in urban walking resources has been garnering increasing scholarly attention. However, there is still no widely accepted tool for assessing walkability, making results difficult to compare across studies. In addition, the ways in which walkability equity is typically defined and measured often overlook China’s local context. Therefore, this study develops a comprehensive walkability evaluation framework for Kunming’s main urban area using open-source data and census information, synthesizing 15 indicators across five dimensions (connectivity, accessibility, suitability, sociability, and aesthetics) analyzed through the Catastrophe Theory models (CT models). Furthermore, spatial autocorrelation, the Concentration Index (CI), and an interpretable machine learning framework (Random Forest-SHAP) are employed to examine the relationships between community walkability disparities and socio-economic factors for a spatial justice assessment. The results show the following: (1) Community walkability in the main urban area of Kunming exhibits a “core–periphery” spatial distribution pattern, where connectivity, accessibility, and sociability follow the general pattern, while suitability and aesthetics display heterogeneous spatial distributions. (2) The social differentiation characteristics of community walkability in Kunming’s main urban area correlate significantly with age structure, hukou registration, and social status, but show limited association with ethnicity and economic status. These findings challenge Western-centric social differentiation paradigms and underscore the context-specific nature of walkability equity in China, thus providing new perspectives for the understanding of built environment justice in the context of Chinese cities.

Water resources constitute a foundational strategic resource, and the efficiency of their spatial allocation profoundly impacts national sustainable development. This study integrates multi-regional input–output modeling, complex network analysis, and exploratory spatiotemporal data analysis methods to systematically examine the patterns, network structures, and spatiotemporal evolution characteristics of virtual water flows across 30 Chinese provinces from 2010 to 2023. Findings reveal the following: Virtual water flows underwent a three-stage evolution—“expansion–convergence–stabilization”—forming a “core–periphery” structure spatially: eastern coastal and North China urban clusters as input hubs, while East–Northeast–Northwest China served as primary output regions; The virtual water flow network progressively tightened and segmented, evidenced by increased network density, shorter average path lengths, and enhanced clustering coefficients and transitivity. PageRank analysis reveals significant Matthew effects and structural lock-in within the network; LISA time paths indicate stable spatial structures in most provinces, yet dynamic characteristics are prominent in node provinces like Guangdong and Jiangsu. Spatiotemporal transition analysis further demonstrates high overall system resilience (Type0 transitions accounting for 47%), while abrupt transitions in provinces like Hebei and Liaoning are closely associated with national strategies and industrial restructuring. This study provides theoretical and empirical support for establishing a coordinated allocation mechanism between physical and virtual water resources and formulating differentiated regional water governance policies.

A simplified neutron-kinetics model for recriticality calculations has been developed and implemented within the severe accident code MELCOR. The model partitions the core into active and inactive regions and determines neutron flux using factorization with adiabatic and prompt-jump approximations. Homogenization of pre-calculated core cell multiplication factors, together with Doppler and xenon reactivity defects calculated by perturbation theory, avoids explicit treatment of cross-sections. This approach allows recriticality analysis to be performed seamlessly within MELCOR at standard time-steps and computational cost. Comparisons with SARA project simulations show reasonable agreement. Integrated with MELCOR, the model extends its capabilities to predict reactivity, recriticality timing, fission power, fuel temperatures, and xenon transients. The model was applied to station blackout scenarios in a Nordic BWR with varying low-pressure safety injection timing and two decay-heat curves. Simulations suggest that the time window for recriticality may be substantial if the core periphery remains intact and coolant flow through a breached vessel is limited. In cases where recriticality occurred, fission power evolution was irregular, and even relatively low fission power accelerated containment heat-up and pressurization. These results demonstrate that the simplified model provides an efficient tool for investigating recriticality phenomena, their impact on severe accident progression, and the effectiveness of mitigation strategies under uncertainty and sensitivity analyses. • A simplified neutron kinetics model for recriticality analysis in severe accidents is developed. • The model is implemented in the MELCOR code using its built-in control functions. • Simulations indicate that late-stage recriticality may occur if the core periphery remains intact.

ABSTRACT This article provides a spatial justice critique of the urban sustainability agenda. Reflecting on the apparent growing discontent against urban sustainability policies, we argue that this backlash can partly be traced to how this agenda has favoured city centres and overlooked spatial dynamics and injustices that fuel core–periphery polarisation. The urban sustainability agenda tends towards ‘urban triumphalism’, while framing suburban areas and spaces as inherently problematic. We propose to widen the geographical scope of the urban sustainability agenda, and discuss policy directions that may contribute to this, with the view to achieving greater legitimacy, more inclusivity and value pluralism.

Brain drain, also referred to as brain gain, represents a global phenomenon and is a highly debated topic in today's world. It exerts adverse effects on developing countries, while yielding beneficial outcomes in developed nations. This article relies on secondary data sources, which have been collected from various published documents, and employs dependency and world system theory, particularly focusing on the unequal core–periphery dynamics. The discussion traces back to the Paleolithic era, elaborating on the out-of-Africa hypothesis, with significant occurrences noted between 1960 and 1970 AD. The primary focus of this article is the dual impacts of brain drain in Nepal. Annually, over seven hundred thousand individuals leave Nepal, with a significantly lower number of brains gain in comparison to the earlier trends. Factors such as inadequate infrastructure, insufficient quality education, limited job opportunities, poverty, corruption, and political instability have led to the migration of a majority of human resources from Nepal, resulting in detrimental effects on the social, economic, and cultural sectors in the country. Brain drain, also referred to as brain gain, represents a global phenomenon and is a highly debated topic in today's world. It exerts adverse effects on developing countries, while yielding beneficial outcomes in developed nations. This article relies on secondary data sources, which have been collected from various published documents, and employs dependency and world system theory, particularly focusing on the unequal core–periphery dynamics. The discussion traces back to the Paleolithic era, elaborating on the out-of-Africa hypothesis, with significant occurrences noted between 1960 and 1970 AD. The primary focus of this article is the dual impacts of brain drain in Nepal. Annually, over seven hundred thousand individuals leave Nepal, with a significantly lower number of brains gain in comparison to the earlier trends. Factors such as inadequate infrastructure, insufficient quality education, limited job opportunities, poverty, corruption, and political instability have led to the migration of a majority of human resources from Nepal, resulting in detrimental effects on the social, economic, and cultural sectors in the country.

Knowledge flow is essential for regional innovation and a critical pathway to building a high-quality innovation system in China. This study constructs an inter-provincial knowledge flow network based on citation relationships in Chinese literature, applies social network analysis to examine the evolution of its characteristics, and employs the Chinese Library Classification number to represent content categories. The results indicate that (1) inter-provincial knowledge flow in China is gradually strengthening, while differences in provincial importance are narrowing and dependence on key provinces is declining; (2) Beijing, Shanghai, Jiangsu, and Hubei remain central in driving knowledge innovation within the network; (3) a core–periphery structure persists, although the number of provinces in the core is decreasing and correlations between the core and peripheral regions are increasing; and (4) the country’s leading economic provinces and cultural centers continue to play a prominent role in the output of scientific innovation.

The regional differences in education have an impact on educational equity, making them an important issue for investigation. The importance of the regional differences is relatively apparent in extant research on teaching and how it is communicated. This study focuses on the characteristics of research communication among teachers within counties, examining their regional differences. Data on research communication are collected from 71 geography teachers in 9 units in City A and 97 geography teachers in 27 units in County B in the southern and northern regions of Jiangsu Province, China. Social network analysis (SNA) methods are used to compare network density, cohesive subgroups, centrality, and core–periphery structures. This study finds similarities and differences in the characteristics of research communication between the two regions. For example, the density of communication among geography teachers in County B is greater than it is in City A, and the network structure in City A is center–dispersed while in County B it is interwoven. The study also discusses the potential impact of research communication differences on education equity, conducting analysis and providing explanations for the observed differences. Furthermore, the study aims to develop a reference that could be used to eliminate educational inequality caused by regional differences and to prepare for the establishment of SNA standards for regional research communication.

This paper highlights the significance of mesoscale structures, particularly the core-periphery structure, in financial networks for portfolio optimization. We build portfolios of stocks belonging to the periphery part of the Minimum Spanning Trees and Planar maximally filtered subgraphs of the underlying network of stocks created from Pearson correlations between pairs of stocks and compare its performance with some well-known strategies of Pozzi et. al. hinging around the local indices of centrality in terms of the Sharpe ratio, Sortino ratio, information ration and average return. Our findings reveal that these portfolios consistently outperform traditional strategies and further the core-periphery profile obtained is statistically significant across time periods. These empirical findings substantiate the efficacy of using the core-periphery profile of the stock market network for both inter-day and intraday trading and provide valuable insights for investors seeking better returns.

Small and medium-sized enterprises (SMEs) constitute the backbone of the EU economy, yet their uneven digital transformation raises challenges for competitiveness and territorial cohesion. This article examines the organizational and spatial aspects of SME digitalization across the European Union using Flash Eurobarometer 486 data and latent class analysis (LCA) combined with Bayesian multilevel multinomial regression. The results reveal four SME digitalization profiles—Digitally Conservative Backbone; Partially Digital and Upgrading; Digitally Advanced and Diversified; and Focused Digital Integrators—reflecting diverse adoption patterns of key technologies such as AI, big data and cloud computing. Digitalization is shaped by organizational factors (firm size, value chain integration, digital barriers) and territorial factors (urbanity, border proximity, national digital infrastructure as measured by the Digital Economy and Society Index, DESI). Contrary to linear modernization assumptions, digital adoption follows geographically embedded trajectories, with sectoral uptake occurring even in low-DESI or non-urban regions. These results challenge core–periphery models and highlight the significance of place-based innovation networks. The study contributes to modernization theory and regional innovation systems by showing that digital inequalities exist not only between countries but also within regions and among adoption profiles, emphasizing the need for nuanced, multi-level digital policy approaches across Europe.

We use transparency data published by the European Commission (EC) to perform a quantitative analysis of the structure and dynamics of stakeholder consultation in the EU policy-making process. We analyze the data through the prism of network theory by constructing a hypergraph whose nodes are EC officials and stakeholders, and hyperedges connect entities that participate in the same meetings. Our analysis highlights the presence of a hierarchical core-periphery structure, with a few well-connected entities that occupy the center of the network and enjoy a stable integration in the EC policy-making process. Examination of the core composition reveals that companies and trade associations maintain closer relationships with the EC. A regression analysis shows that lobbying efforts and company size are significant predictors of company centrality, independent of other objective characteristics. Our findings provide quantitative evidence supporting the perception of lobbying as a tool dominated by well-connected actors, while also revealing heterogeneous lobbying strategies across stakeholder groups.