GCRIS

Now showing 1 - 3 of 3

Spatial Proximity and Accessibility Patterns of X-Minute Cities
(Elsevier Ltd, 2026) Östh, John; Türk, Umut; Kourtit, Karima; Nijkamp, Peter
The 15-minute city concept has gained prominence in urban planning as a framework linking proximity, mobility, and quality of life at the intra-urban scale. An open question is whether this concept remains meaningful when applied to spatially connected urban regions or national urban systems. To address this issue, the new X-minute city concept allows proximity thresholds to vary with spatial context, mobility conditions, and service distribution. This paper develops an operational framework with the aim to examine and highlight spatial accessibility patterns from an X-minute city perspective, using the relatively urbanized area of the Netherlands as a national-scale case study. Accessibility is analyzed at the building level using OpenStreetMap data and a combination of object-based k-nearest-neighbor measures, distance-decay functions, inequality metrics, Average Nearest Neighbor analysis, and quantile regression. Concepts from central place theory are employed as an interpretive lens to understand service clustering and accessibility patterns, rather than as a formal model to be tested. The results show pronounced spatial disparities in accessibility between urban and rural areas, as well as substantial variation within cities. Major urban centers such as Amsterdam, Rotterdam, and Utrecht exhibit high accessibility levels due to dense service provision, while peripheral and rural areas face systematically lower accessibility. Next accessibility outcomes also differ sharply across population groups. Elderly residents and groups reliant on walking experience the highest levels of inequality, with accessibility distributions remaining highly uneven at short-distance thresholds. Cycling expands the range of effective activity spaces and reduces inequality, but does not offset structural disadvantages in areas with sparse service provision. The findings point to the limits of uniform proximity targets and reveal the need for context-sensitive accessibility planning that explicitly accounts for service distribution, mobility constraints, and population heterogeneity within national urban systems.
Citation - WoS: 1
Citation - Scopus: 1
A Comparative Study of Existing and Current On-Site Documentation of Anatolian Seljuk Kümbets
(Elsevier Ltd, 2025-12) Güzelci, O.Z.; Türel, A.
During the Anatolian Seljuk period (1077–1307), monumental tombs known as kümbets emerged as a distinct architectural typology in present-day Türkiye. 2D drawings of these structures, produced since the early 20th century, contain inconsistencies that necessitate verification and accurate documentation. This study digitally documents Anatolian Seljuk kümbets in 3D to generate updated 2D sections reflecting their current condition and compares these with previously published drawings. The methodology includes collecting available 2D sections, digitally documenting kümbets through field studies, generating new 2D sections from 3D models, and systematically comparing these datasets. Two image-based metrics are employed in the comparison: the Exact Pixel Match Ratio (EPMR), which evaluates pixel-level alignment, and the Structural Similarity Index Measure (SSIM), a standard indicator for visual similarity. The results provide a comparative framework for assessing previous drawings and present a verified, up-to-date dataset of kümbet sections for future research. © 2025 Elsevier B.V., All rights reserved.
Citation - Scopus: 2
Deformation Behavior of Nanostructured Aluminum: Experiment and Computational Study
(Elsevier Ltd, 2023-04) Deka, Surja; Mozafari, Farzin; Mallick, Ashis K.
Nanocrystalline metals have been processed from powder predecessors in recent times in significant ways, and nowadays, materials are starting to be manufactured which are not only strong but also ductile. Nanocrystalline aluminum (Average grain size 51 nm) was synthesized through high-energy ball milling at the room temperature of microcrystalline powder. The particle size and crystallite sizes were obtained by Williamson Hall and found to be in good correlation with transmission spectroscopy (TEM) data. There was a significant increase in the mechanical properties of nanostructured aluminum in comparison to coarse-grained aluminum. Moreover, a phenomenological model of large-deformation, isotropic, rate-dependent plasticity is developed, which takes into account pressure dependency, plastic dilatation, and non-normal flow. The model has been incorporated into a finite element program. Compression and tension experiments were performed on nanocrystalline aluminum, and the constitutive parameters within the model were estimated from these experiments. The present study shows that the constitutive model successfully simulates the mechanical response of nanocrystalline aluminum with reasonable accuracy using our numerical finite-element capability. © 2023 Elsevier B.V., All rights reserved.

Scopus İndeksli Yayınlar Koleksiyonu

Browse

Filters

Settings

Sort By

Results per page

Search Results