Local Boundary Research Articles

On the Local Boundary Representations of Locally $$C^*$$-Algebras

On the Local Boundary Representations of Locally $$C^*$$-Algebras

Local and translocal social capital in flood adaptation: evidence from Indonesian coastal communities

ABSTRACT Environmental change and sea level rise challenge urban coastal communities, especially in the Global South. Existing hazard research emphasises the vital role of social capital in adaptation but often overlooks translocal social capital, which encompasses social support and resources that extend beyond local boundaries and connect people at different places. To reduce this research gap, this study investigates the impact of local and translocal social capital on flood-prone households in Padang and Denpasar, Indonesia, using survey data (N = 620) and social network data (N = 1169). The results show translocal contacts provide more emotional, moral, financial, and material support, while local contacts share flood-related knowledge, skills, advice, and practical support. Further, our findings show that the effectiveness of social support varies: local support is strengthened by community ties and diverse forms of support, whereas translocal support's significant role in mental health relies on intimacy and reliability in strong personal relationships. Well-connected support contacts help households to access broader social networks. These findings highlight the different roles of local and translocal social capital in long-term adaptation, which partly complement each other. Households benefit from maintaining diverse support networks, with each type of social capital playing distinct yet interdependent roles in enhancing resilience against environmental changes.

The linearization of the boundary rigidity problem for MP-systems and generic local boundary rigidity

Abstract We consider an MP -system, that is, a compact Riemannian manifold with boundary, endowed with a magnetic field and a potential. On simple MP -systems, we study the MP -ray transform in order to obtain new boundary rigidity results for MP -systems. We show that there is an explicit relation between the MP -ray transform and the magnetic one, which allows us to apply results from Dairbekov et al (2007 Adv. Math. 216 535–609) to our case. Regarding rigidity, we show that there exists a generic set G m of simple MP -systems, which is open and dense, such that any two MP -systems close to an element in it and having the same boundary action function, must be k-gauge equivalent.

Polity Size and Local Government Performance: Evidence from India

Developing countries have increasingly decentralized power to local governments. This paper studies the implications of a central element of decentralization (polity size) using population-based discontinuities that determine local government boundaries for over 100,000 Indian villages. Over the short and long run, individuals allocated into local governments with smaller populations have better access to public goods. We provide suggestive evidence that these results are related to heightened civic engagement and stronger political incentives, but not to other mechanisms such as elite capture. (JEL D72, H41, H75, H76, O17, O18, R50)

Correlations between local chemical fluctuations and grain boundary strength in Ti-Zr-Nb-Ta-Mo refractory multi-principal element alloys

Ti-Zr-Nb-Ta-Mo refractory multi-principal element alloys typically exhibit high yield strength while tensile ductility tends to be poor. In this study, we found that even after solid solution treatment of Ti-Zr-Nb-Ta-Mo alloys, significant change in ductility occur due to the local chemical fluctuations. Ta's dramatic chemical fluctuations cause variations in atomic-scale strain fields, leading to reduced grain boundary strength and brittle fracture. First-principles calculations show that (Ti, Zr)-rich at the grain boundaries increases the delocalization of valence electrons, leading to longer bond lengths and reduced crystal orbital bond index values, thereby causing grain boundary embrittlement. Our findings explore the root causes of brittleness in Ti-Zr-Nb-Ta-Mo alloys at the atomic and electronic scales, providing not only a method to analyze grain boundary embrittlement using bond length, electronic localization function and crystal orbital bond index, but also a theoretical guidance for improving the mechanical properties via grain boundary structure optimization.

Multi-hazard, multidimensional disaster risk validation in selangor’s three urban districts, Malaysia

Considering the increasing impact of natural hazard-related disasters in Malaysia, understanding and evaluating integrated disaster risk must consider multi-hazard and multidimensional vulnerability at the local level, particularly in developing industrial nations like Malaysia. Therefore, this study proposes an improved methodology for conducting an integrated disaster risk assessment index (IDRI) mapping to measure disaster risk within local administrative boundaries in Malaysia. In this study, multi-hazard spatial overlapping combined two common hazards in Malaysia, which are floods and landslides. This study used multidimensional vulnerability, which encompasses six dimensions, 16 subdimensions, and 54 indicators. Researchers applied this approach in three urban districts of Selangor, Malaysia: Sepang, Kuala Langat, and Hulu Langat, which are located within the Langat River catchment and consist of 17 subdistricts. Overall, 32.9% of the total study area was found to be at risk, with 4.3% in the very high-risk area. In comparison with the latest flood events in 2021, the IDRI components were highly correlated with disaster impact. In conclusion, the contribution of this study provides a novel perspective on disaster risk assessment by addressing several types of hazards and multidimensional vulnerability, as compared to the previous methodology focusing on a single hazard and a physical vulnerability factor.

Selective and multi-scale fusion Mamba for medical image segmentation

Given the high variability in the morphology and size of lesion areas in medical images, accurate medical image segmentation requires both precise positioning of global contours and careful processing of local boundaries. This emphasizes the importance of fusing multi-scale local and global features. However, existing CNN and Transformer-based models are often limited by high parameter counts and complex calculations, making it difficult to efficiently integrate these features. To address this challenge, we proposed two innovative optimization architectures: Selective Fusion Mamba (SF-Mamba) and Multi-Scale Fusion Mamba (MF-Mamba). SF-Mamba can flexibly and dynamically adjust the fusion strategy of local and global features according to the characteristics of the lesions, effectively handling segmentation tasks with variable morphology. MF-Mamba enhances the model’s segmentation ability for lesions of different sizes by capturing global information across scales. Based on these two structures, we constructed a lightweight SMM-UNet model, which not only significantly reduces the computational burden (with only 0.038M parameters) but also demonstrates excellent generalization ability and can efficiently adapt to various types of medical images. Extensive tests on the ISIC2017, ISIC2018, and BUSI public datasets show that SMM-UNet achieves excellent segmentation performance with an extremely low parameter cost.

Identifying Rare Events in Quantum Molecular Dynamics of Nanomaterials with Outlier Detection Indices.

Nanoscale and condensed matter systems evolve on multiple length- and time-scales, and rare events such as local phase transformation, ion segregation, defect migration, interface reconstruction, and grain boundary sliding can have a profound influence on material properties. We demonstrate how outlier detection indices can be used to identify rare events in machine-learning based, high-dimensional molecular dynamics (MD) simulations. Designed to order data-points from typical to untypical, the indices enable one to capture atomic events that are hard to detect otherwise. We demonstrate the approach with a nanosecond MD simulation of a grain boundary in a metal halide perovskite that is extensively studied for solar energy and optoelectronic applications. The method captures the initial grain boundary sliding and a spontaneous fluctuation half a nanosecond later, both events giving rise to persistent deep electronic trap states that impact charge carrier lifetime and transport and material performance. The approach offers a generalizable and simple method for identifying outlier events in complex condensed matter, molecular, and nanoscale systems.

Localized space-time Trefftz method for diffusion equations in complex domains

This paper introduces an advanced localized space-time Trefftz method tackling boundary value predicaments within complex two-dimensional domains governed by diffusion equations. In contrast to the widespread space-time collocation Trefftz method, which typically produces dense and ill-conditioned matrices, the proposed strategy employs a localized collocation scheme to remove these constraints. In particular, this is beneficial in multi-connected configurations or when dealing with significant variations in field values. To the best of our knowledge, this is the first space-time collocation Trefftz method adaptation, which is referred to as the localized space-time Trefftz method in this paper. The latter combines the space-time collocation Trefftz method principles, which allows to eliminate the need for mesh and numerical quadrature in its application. The localized space-time Trefftz method represents each interior node expressed as a linear blend of its immediate neighbors, while the space-time collocation Trefftz method applies numerical techniques within distinct subdomains. A sparse system of linear algebraic equations with internal points satisfying the governing equation, and boundary points satisfying the boundary conditions, allows to obtain numerical solutions using matrix systems. The localized space-time Trefftz method retains the easy-to-use properties and mesh-free structure of the space-time collocation Trefftz method, and it mitigates its ill-conditioning characteristics. Due to the localization principle and the consideration of overlapping subdomains, the solutions in the proposed localized space-time Trefftz method are more simply and compactly expressed compared with those in the space-time collocation Trefftz method, especially when dealing with multiply-connected domains. Numerical examples for simply-connected and multiply-connected domains are then provided to demonstrate the high precision and simplicity of the proposed localized space-time Trefftz method. The obtained results show that the latter has very high accuracy in solving two-dimensional diffusion problems. Compared with the traditional space-time collocation Trefftz method, the proposed mesh-free strategy yields solutions with higher precision while significantly reducing the instability.

Classical echoes of quantum boundary conditions

Abstract We consider a non-relativistic particle in a one-dimensional box with all possible quantum boundary conditions that make the kinetic-energy operator self-adjoint. We determine the Wigner functions of the corresponding eigenfunctions and analyze in detail their classical limit, governed by their behavior in the high-energy regime. We show that the quantum boundary conditions split into two classes: all local and regular boundary conditions collapse to the same classical boundary condition, while a dependence on singular non-local boundary conditions persists in the classical limit.

Revealing Local Grain Boundary Chemistry and Correlating it with Local Mass Transport in Mixed-Conducting Perovskite Electrodes.

Grain boundary (GB) mass transport, and chemistry exert a pronounced influence on both the performance and stability of electrodes for solid oxide electrochemical cells. Lanthanum strontium cobalt ferrite (LSCF6428) is applied as a model mixed ionic and electronic conducting (MIEC) perovskite oxide. The cation-vacancy distribution at the GBs is studied at both single and multi-grain scales using high-resolution characterization techniques and computational approaches. The accumulation of oxygen vacancies ( ) in the GB region, rather than necessarily at the GB core, results in an enhancement of the oxygen diffusivity by 3 - 4 orders of magnitude along the GBs (Dgb). At 350°C, the oxygen tracer diffusion coefficient (D*) is measured as 2.5 × 10-14 cm2s-1. The Dgb is determined to be 2.8 × 10-10 cm2s-1 assuming a crystallographic GB width (δcrystal) of 1nm, and 2.5 × 10-11 cm2s-1 using a chemically measured δchem of 11.10nm by atom probe tomography (APT). The origin of the concomitant changes in the cation composition is also investigate. In addition to the host cations, strong Na segregation is detected at all the GBs examined. Despite the low (ppm) level of this impurity, its presence can affect the space charge potential (Φ0). This, in turn, will influence the evolution of GB chemistry.

Developing a Bookless Library for Enhanced Literacy in Islamic Boarding Schools

Abstract: The 4.0 industrial revolution compels educational institutions, including Islamic boarding schools, to adopt advanced digital library services for enhanced literacy. General Background: Many libraries, such as that of Al Fattah Islamic Boarding School in Sidoarjo, still depend on physical books and lack accreditation, resulting in outdated collections. Specific Background: There is a significant gap in structured digital library frameworks that provide extensive access to both general and Islamic literature. Aims: This study aims to develop a school development plan for a Bookless Library that enhances digital literacy. Results: Employing a Research and Development (R&D) approach, the study outlines a five-year strategic plan for implementing a digital library, utilizing QR codes for quick access to resources. Novelty: It proposes a global access model for the Bookless Library, allowing users beyond the server's immediate area to engage with digital resources. Implications: The expected outcome is a dynamic learning environment that promotes literacy and positions Al Fattah Islamic Boarding School competitively in a technology-driven educational landscape. Highlights: Technological Adaptation: The implementation of digital libraries addresses the evolving needs of students in the 4.0 industrial revolution. Resource Accessibility: QR codes facilitate instant access to a vast array of digital resources, enhancing learning opportunities. Global Reach: The proposed Bookless Library model allows users beyond local boundaries to engage with diverse literature. Keywords: Digital Library, Bookless Library, Islamic Boarding School, Literacy Enhancement, Research and Development

Terminal Doppler Weather Radar Retrievals in Complex Terrain during a Summer High Ozone Period

Abstract Out of the 45 radars composing the Terminal Doppler Weather Radar (TDWR) network, 21 are located in areas of complex terrain. Their mission to observe low-level wind shear at major airports prone to strong shear-induced accidents puts them in an ideal position to fill critical boundary layer observation gaps within the NEXRAD network in these regions. Retrievals such as velocity azimuth display and velocity volume processing (VVP) are used to create time-height profiles of the boundary layer from radar conical scans, but assume that a wide area around the radar is horizontally homogeneous. This assumption is rarely met in regions of complex terrain. This paper introduces a VVP retrieval with limited radius to make these profiling techniques informative for flows affected by topography. These retrievals can be applied to any operational radar to help examine critical boundary layer processes. VVP retrievals were derived from the TDWR for Salt Lake City International Airport, TSLC, during a summertime high ozone period. These observations highlighted thermally driven circulations and variations in boundary layer depth at high vertical and temporal resolution and provided insight on their influence on air quality. Significance Statement Residents in many urban areas of the United States are exposed to elevated ozone concentrations during the summer months. In complex terrain, thermally driven circulations and terrain-forced flows affect chemical processes by modulating mixing and transport. A novel technique to monitor local boundary layer conditions on small horizontal length scales was applied to data from the Terminal Doppler Weather Radar located near Salt Lake City International Airport during a multiday high ozone event, and effects of these flows on ozone concentrations are illustrated. This technique can be applied to other operational weather radars to create long-term and real-time records of near-surface processes at high vertical and temporal resolution.

Computational influences of convection micropolar fluid influx and permeability on characteristics of heating rate and skin friction over vertical plate

This manuscript merits at examining of an embedded orthogonal plate inside porous domain exposed to uniform heat influx to elaborate on how micro polar fluid factors and permeability characteristic affect the local skin friction, heating rate, and angular velocity inside boundary layer. The plate is subjected to forced convective micro polar fluid influx under steady, incompressible, and viscous circumstances. To facilitate dependable numerical solution, similarity approach is implemented to mutate set of coupled governing equations relevant to the adopted study into a constrained dimensionless differential equations. Computational analysis has been executed hiring Runge-Kutta scheme by Matlab function bvp4c to settle the governing equations. Study's results are highlighted graphically the impact of micro polar fluid factors on the local skin friction, heating rate, and angular velocity curves. High degree of acceptability of present findings compare with prior research results. It is found that the rising of Darcy parameter drives to decrease linearly both heating rate and local skin friction. Among the examined factors, the benchmark parameter of decreasing skin friction is the porosity. Additionally, it is found that an increasing of Prandtl number and micro rotation element lead to enhance Nusselt number. Once curves of micro rotation are interfered at certain distance from the plate due to increase in porosity, Darcy, Forchheimer's, and microelement rotation, the micro rotation curves are inverted.

Multi-Scale Meteorological Impact on PM2.5 Pollution in Tangshan, Northern China.

Tangshan, a major industrial and agricultural center in northern China, frequently experiences significant PM2.5 pollution events during winter, impacting its large population. These pollution episodes are influenced by multi-scale meteorological processes, though the complex mechanisms remain not fully understood. This study integrates surface PM2.5 concentration data, ground-based and upper-air meteorological observations, and ERA5 reanalysis data from 2015 to 2019 to explore the interactions between local planetary boundary layer (PBL) structures and large-scale atmospheric processes driving PM2.5 pollution in Tangshan. The results indicate that seasonal variations in PM2.5 pollution levels are closely linked to changes in PBL thermal stability. During winter, day-to-day increases in PM2.5 concentrations are often tied to atmospheric warming above 1500 m, as enhanced thermal inversions and reduced PBL heights lead to pollutant accumulation. Regionally, this aloft warming is driven by a high-pressure system at 850 hPa over the southern North China Plain, accompanied by prevailing southwesterly winds. Additionally, southwesterly winds within the PBL can transport pollutants from the adjacent Beijing-Tianjin-Hebei region to Tangshan, worsening pollution. Simulations from the chemical transport model indicate that regional pollutant transport can contribute to approximately half of the near-surface PM2.5 concentration under the unfavorable synoptic conditions. These findings underscore the importance of multi-scale meteorology in predicting and mitigating severe wintertime PM2.5 pollution in Tangshan and surrounding regions.

Görtler Vortices in the Shock Wave/Boundary-Layer Interaction Induced by Curved Swept Compression Ramp

This study builds on previous research into the basic flow structure of a separated curved swept compression ramp shock wave/turbulence boundary layer interaction (CSCR-SWBLI) at the leading edge of an inward-turning inlet. We employ the ice-cluster-based planar laser scattering (IC-PLS) technique, which integrates multiple observation directions and positions, to experimentally investigate a physical model with typical parameter states at a freestream Mach number of 2.85. This study captures the fine structure of some sections of the flow field and identifies the presence of Görtler vortices (GVs) in the CSCR-SWBLI. It is observed that due to the characteristics of variable sweep angle, variable intensity interaction, and centrifugal force, GVs exhibit strong three-dimensional characteristics in the curved section. Additionally, their position is not fixed in the spanwise direction, demonstrating strong intermittence. As the vortices develop downstream, their size gradually increases while the number decreases, always corresponding to the local boundary layer thickness. When considering the effects of coupling of bilateral walls, it is noted that the main difference between double-sided coupling and single-sided uncoupling conditions is the presence of a large-scale vortex in the central plane and an odd number of GVs in the double-sided model. Finally, the existence of GVs in CSCR-SWBLI is verified through the classical determine criteria Görtler number (GT) and Floryan number (F) decision basis.

The poverty of postmodernist constructivism: And a case for naturalism out of Hume, Darwin, and Wittgenstein

AbstractThis essay develops a naturalist framework based on Hume, Darwin, and Wittgenstein against postmodernist constructivism. That framework claims universal features of human biology, cognition, and behavior to explain our cultural histories, running contrary to two core constructivist doctrines of postmodernist scholarship: mutual opacity and epistemic violence. Mutual opacity posits the incommensurability of systems rooted in differing contexts, cultures, and group identities, while epistemic violence morally impugns the extension of the knowledge claims of any such system beyond its strictly localized boundaries. This is the extension that universalist approaches, like naturalism, are recriminated against owing to their claims to discover encompassing standpoint‐independent and transcultural features of human constitution and modes of life. Comparative evaluation of these approaches exposes the failure of postmodernist constructivism to explain parallel practices, conventions, and institutions across human cultural histories, which universalist naturalism succeeds at, while moreover revealing how this failure undermines its agendas of social justice.

Quantifying urban climate response to large-scale forcing modified by local boundary layer effects

Over the past two decades, the joint manifestation of global warming and rapid urbanization has significantly increased the occurrence of heatwaves and the formation of urban heat islands in temperate cities. Consequently, this synergy has amplified the frequency and duration of periods with tropical nights (TNs) in these urban areas. While the occurrences of such extreme events demonstrate irregular and nonlinear annual patterns, they consistently manifest a discernible rising decadal trend in local or regional climatic data. In urban regions situated amidst hilly or mountainous landscapes, changing wind directions—often associated with uphill or downhill thermal flows—profoundly impact the spread and dispersion of heat-related pollution, creating unique natural ventilation patterns. Using the Lausanne/Pully urban area in Switzerland as examples of hilly and lakeshore temperate cities, this study explores the influence of wind patterns and natural urban ventilation on the nonlinearity of recorded climatic data within an urban environment. This study integrates a mesoscale numerical weather prediction model (COSMO-1), a microscale Computational Fluid Dynamics (CFD) model, field observations, variational mode decomposition technique, and statistical analysis to investigate how wind speed and direction critically influence the nonlinearity of recorded long-term trends of extreme events, specifically focusing on the frequency and duration of TNs in lakeshore and hilly cities. The results strongly indicate a direct correlation between the frequency of TNs and the occurrence of specific moderate wind patterns. These wind patterns are exclusively captured by the microscale CFD model, unlike the mesoscale model, which neglects both urban morphology and complex hilly terrains. The impact of temporal and spatial variability of the wind field on long-term observations at fixed measurement stations suggests that caution should be exercised when relying on limited spatial measurement points to monitor and quantify long-term urban climate trends, particularly in cities located in complex terrains.

Short-term fluctuating and long-term divergent selection on sympatric Monkeyflowers: insights from decade-spanning reciprocal transplants.

Sympatric species are often locally adapted to distinct microhabitats. However, temporal variation may cause local maladaptation and species boundary breakdown, especially during extreme climatic events leading to episodic selection. Repeated reciprocal transplants can reveal the interplay between short and long-term patterns of natural selection. To examine evolutionary trajectories of sympatric Monkeyflowers adapted to different niches, Mimulus guttatus and M. laciniatus, we performed three replicated transplants and combined them with previous experiments to leverage a dataset of five transplants spanning 10 years. We performed phenotypic selection analyses on parents and hybrids in parental habitats in Yosemite NP, CA during years of drastically differing snowpack. If there is ecological isolation, then we predicted divergent phenotypic selection between habitats in line with species' differences and local adaptation. We found interannual fluctuations in phenotypic selection, often in unpredicted directions. However, a combined-year analysis detected longer-term divergent selection on flowering time, a key temporally isolating and adaptative trait, suggesting that selection may reinforce species boundaries despite short-term fluctuations. Finally, we found temporal variation in local adaptation with M. laciniatus locally adapted in low snowpack years, while an extremely high snowpack year contributed to average local maladaptation of M. guttatus.

Study of political developments in democratic, communist and dictatorial systems and their impact on power, governance and human rights

In the current era, the world is experiencing profound political and economic shifts, marking a departure from the norms that dominated the pre-industrial period. Notably, the dissolution of feudal and communal systems, which were emblematic of an economy rooted in pastoral ideologies, has been underway since the French Revolution. This transformative period has not only reshaped global dynamics but also led to the reconstitution of modern state structures within the context of institutional states. This research delves into the evolving patterns of political changes and their economic repercussions in the contemporary global landscape. Our study aims to decipher the dynamics of international transformations within the global political arena and explore their interconnections with the emerging world order. Furthermore, we have endeavored to trace the philosophical political roots that underpinned these economic systems, examining their genesis and subsequent influence on political developments across various regimes, with a particular focus on implications for human rights. An analytical methodology underpins our examination of these political transformations. Central to our inquiry is the following pivotal question: What is the impact of developments in political and economic systems in the contemporary world on authority, governance, and human rights? To address this question, we deemed it necessary to discuss three topics related to political transformation, presenting an analysis for each of the following axes: 1-Circumstances and history of modern political transformations. 2-Modern political demands, compared to advanced political aspirations. 3-Human rights, between liberal propaganda and democracy. Our findings reveal that political variables have undergone substantial changes that significantly influence political ideologies, the conceptualization of authority, and human rights considerations. Among these influential factors are: Globalization and Technology: Technological advancements and the expansion of global communications via the Internet have opened new avenues for political discourse and interaction. This development transcends local boundaries, positioning politics as a globally interconnected phenomenon. Social and Cultural Transformations: There has been a significant shift in social and cultural paradigms, particularly in the heightened awareness of human rights. This shift has broadened the scope of political thought and necessitated the integration of these issues into both national and international political dialogues. Economic Transformations: The evolution of economic structures, spurred by technological progress and globalization, has profound implications for political theories concerning the equitable distribution of wealth, economic opportunities, poverty alleviation, and addressing economic disparities.