Search Results (723)

Tableware objects such as plates, bowls, and cups are usually textureless, uniform in color, and vary widely in shape, making it difficult to apply conventional pose estimation methods that rely on texture cues or object-specific CAD models. These limitations present a significant obstacle to robotic manipulation in restaurant environments, where reliable six-degree-of-freedom (6-DoF) pose estimation is essential for autonomous grasping and collection. To address this problem, we propose a model-free and texture-free 6-DoF pose estimation framework based on a transformer encoder architecture. This method uses only geometry-based features extracted from depth images, including surface vertices and rim normals, which provide strong structural priors. The pipeline begins with object detection and segmentation using a pretrained video foundation model, followed by the generation of uniformly partitioned grids from depth data. For each grid cell, centroid positions, and surface normals are computed and processed by a transformer-based model that jointly predicts object rotation and translation. Experiments with ten types of tableware demonstrate that the method achieves an average rotational error of 3.53 degrees and a translational error of 13.56 mm. Real-world deployment on a mobile robot platform with a manipulator further validated its ability to autonomously recognize and collect tableware, highlighting the practicality of the proposed geometry-driven approach for service robotics. Full article

The global rapid urbanization intensifies environmental challenges related to climate change, such as air pollution and the urban heat island (UHI) effect in built environments. The need to optimize nature-based solutions (NBSs) is imperative to mitigate climate change and adapt to extreme weather phenomena. Against this background, this review offers an analysis regarding the integration of vertical greenery systems (VGSs) into urban environments so as to capitalize on their environmental, social, and economic benefits. Key aspects of the review include the positive role of VGSs in UHI mitigation, air quality improvement, stormwater management, and biodiversity enhancement, while examining social aspects (i.e., improved well-being and mental health, noise reduction, and urban built aesthetics). Finally, parameters related to economic benefits and energy efficiency are assessed. The submission further analyses the significant challenges that VGSs face, such as high maintenance costs, structural risks, plant health issues, fire hazards, and other limitations (legislative and technical). The crucial need for interdisciplinary collaborations among urban planners, architects, environmental engineers, and stakeholders is highlighted, in order to successfully integrate VGSs into urban buildings. Thus, this paper aims to identify key strategies for optimizing VGSs’ implementation and provide valuable insights for policymakers and researchers aiming to enhance urban sustainability through vertical greening. Full article

Selecting optimal measurement points to capture maximum vertical vibration levels induced by metro systems on adjacent buildings is a crucial yet often overlooked task. In this study, an on-site vibration test and simulation analysis of a building near the Nanjing metro line were conducted. A vibration wave screening method based on machine learning algorithms was introduced, with decision trees used to filter anomalous data and supervised learning models to identify data damaged by environmental vibration and to obtain representative vibration inputs. Subsequently, vertical vibration analysis was used to examine the influence of structural components, span lengths, and vertical height on vibration propagation and to quickly determine peak vibration locations. The results showed a positive correlation between span length and maximum vibration levels. Slabs are more sensitive to vibration than columns, with higher levels at the center of slabs than at the edges. Additionally, the vibration amplitude increases and then decreases as the vertical height increases. These findings were confirmed by on-site vibration tests and offer insights for sustainable vibration management in metro-adjacent buildings, supporting resilient infrastructure development. The study also provides guidance for selecting vibration measurement points, enhancing human discomfort assessments to reduce health risks and promote socially sustainable communities. Full article

A practical methodology for estimating regionally optimized Klobuchar coefficients using only International GNSS Service (IGS) Global Ionosphere Map (GIM) data is proposed. The method preserves computational simplicity, enabling near-real-time corrections suitable for accurate GNSS positioning. Utilizing both slant and vertical total electron content (STEC and VTEC) values extracted from GIM as inputs to estimate eight Klobuchar coefficients, robust parameter sets were obtained. Root mean square error (RMSE) analysis was used to compare these models to the standard Klobuchar model. Comprehensive performance evaluations using STEC-derived parameters, encompassing both seasonal and spatial analyses across South Korea, demonstrated significant reductions in ionospheric delay errors, with improvements reaching up to 57% compared to the conventional Klobuchar model. The far less computationally intensive VTEC-based model was applied over a wider region with 120 grid points. Continuous testing of this model over an entire year confirmed consistent enhancements in correction accuracy every day, demonstrating stable performance throughout the period. The developed regional Klobuchar models were further validated indirectly through satellite positioning performance, demonstrating daily RMSE improvements over the standard Klobuchar model ranging from 17.3% to 44.6%. Full article

Grey cast iron brake discs with lamellar graphite (GJL) offer excellent strength and thermal conductivity but are prone to wear and dust emissions. To mitigate these issues, a multilayer coating was applied via Laser Metal Deposition (LMD), comprising a 316L stainless steel base layer and a WC-reinforced top layer. This study examines the microstructural evolution of the coatings under simulated thermomechanical and corrosive conditions using a brake shock corrosion test. Microstructural characterization was performed via Scanning Electron Microscopy (SEM) and Electron Backscatter Diffraction (EBSD), focusing on grain size, orientation, and texture before and after testing. EBSD analysis revealed significant grain coarsening, with sizes increasing from below 20 µm to 30–60 µm, and a shift toward <101> texture. Hardness measurements showed a reduction in the WC-reinforced layer from 478 HV to 432 HV and in the 316L base layer from 232 HV to 223 HV, confirming the influence of thermomechanical stress. SEM analysis revealed a transition from horizontal cracks—caused by residual stress during LMD—to vertical microcracks propagating from the substrate, activated by braking-induced loads. These findings provide insights into the microstructural response of LMD coatings under realistic service conditions and underscore the importance of grain boundary control in designing durable brake disc systems. Full article

Efforts to lower the barriers for 5G uptake have brought forth accelerated innovation rates in a wide range of verticals. Consequently, the demands for 5G experimentation facilities have recently emerged from small- and medium-sized enterprises (SMEs) and 3rd party developers, requiring the abstraction of the complexities of the underlying infrastructure, platform, and related management and orchestration (MANO) systems, especially in multi-domain scenarios. This paper proposes a novel approach towards cross-domain service orchestration, which combines the flexibility of supporting different 5G Service Orchestrators (SOs) in various domains, while preserving compatibility through NetApps. The Cross-domain Service Orchestrator (CDSO) is based on ETSI’s Open Source MANO (OSM), with a Requests Handler module on top, which acts as the main integration point to the different domains’ 5G SOs and other custom systems that are northbound. This would facilitate the interworking among independently orchestrated domains in supporting multi-domain services. The EU Horizon 2020 project, 5GMediaHUB, is presented as a use case, together with a first implementation of the Requests Handler and corresponding integrations. Nonetheless, the proposed approach is vertical-agnostic and is foreseen to accelerate service innovation and digitalization in any industry by laying the foundations in terms of service management and interconnectivity. Full article

This study presents a numerical analysis of a road embankment constructed over soft subsoil and reinforced with geogrids and jet grout columns to enhance stability and reduce deformation. The two-dimensional finite element software PLAXIS (PLAXIS 2D Version 2023.2) was employed to simulate both the static and dynamic behavior of the system under real field conditions, utilizing geotechnical parameters obtained from in situ and laboratory tests. The unreinforced embankment exhibited significant vertical and lateral displacements, attributed to inadequate compaction and insufficient bearing capacity of the foundation soil. Finite element simulations were first used to replicate the observed field performance, confirming the accuracy of the modeling approach. Subsequently, reinforcement strategies involving the integration of jet grout columns and geogrid layers were analyzed to assess their effectiveness. The jet grout columns significantly improved subsoil stiffness, while the geogrid reinforcement contributed to the stabilization of embankment slopes. The results demonstrated a 220% increase in the safety factor and a 65% reduction in total settlement compared to the unreinforced case. Additionally, dynamic analysis revealed that while the embankment maintained marginal stability at a horizontal acceleration of 0.30 g, it failed under a 0.40 g seismic load. These findings highlight the critical role of combined reinforcement techniques and process-based modeling in ensuring not only the stability of road embankments on weak soils but also their contribution to sustainable infrastructure development through improved durability, resource efficiency, and extended service life. Full article

Network reliability refers to a probabilistic measure of a network system’s ability to maintain its intended service functionality within a specified time interval and under given operating conditions. Let $\Omega (n,m)$ be the set of all simple two-terminal networks on n vertices and m edges. If each edge operates independently with the same fixed probability $p\in [0,1]$, then the two-terminal reliability, denoted by $R_2(G,P))$, is the probability that there exists a path between two target vertices s and t. For a given number of vertices n and edges m, there are some graphs within $\Omega (n,m)$ that have higher reliability than others, and these are known as extremely optimal graphs. In this work, we determine the sets of extremely optimal graphs in two classes of two-terminal network with sizes $m={\displaystyle \frac{n(n-1))}{2}}-2$ and $m={\displaystyle \frac{n(n-1))}{2}}-3$, consisting of 2 and 5 networks, respectively. Moreover, we identify one class of graphs obtained by deleting some edges among non-target vertices in the complete two-terminal graph, and we count the number of graphs of this class with size ${\displaystyle \frac{n(n-1)}{2}}-\lfloor {\displaystyle \frac{n-2}{2}}\rfloor \le m\le {\displaystyle \frac{n(n-1))}{2}}-1$ by applying the Pólya counting principle. Full article

Airport-bound access and egress trips comprise a significant portion of total ground transportation trips, especially in regions served by large airports. Connecting urban areas with airports under minimal travel delays can be challenging, with traffic congestion along busy connecting corridors being a common phenomenon. Urban Air Mobility (UAM) is a new transportation mode envisioned to reduce travel times using specific aircraft, such as electric (and non-electric) Vertical or Short Take-off and Landing aircraft (e/VTOLs and STOLs, respectively). The operation of these aircraft requires take-off and landing infrastructure known as vertiports. A strategic infrastructure placement framework was introduced, utilizing and adapting the Capacitated Facility Location Problem (a-CFLP) and the Maximal Covering Location Problem (a-MCLP) with capacity constraints. An adapted capacitated k-means algorithm and a greedy heuristic were considered for the solution of the a-CFLP, while the a-MCLP was formulated as a mixed-integer linear programming problem. The proposed framework was applied in the Chicago Metropolitan Area, revealing that various trade-offs regarding coverage and accessibility, versus operational costs (number of facilities, facility capacity, and service radius), exist. The results showed that, depending on vertiport capacity and service radius capabilities, a range of 5 to 12 vertiports can sufficiently address the demand (above 95% demand coverage) and, with respect to accessibility, serve a moderate UAM demand scenario of 6124 daily requests, as identified for this region. Full article

The transboundary partnership encourages multi-stakeholder efforts to mobilize adaptation funding and services for adaptation governance. However, challenges exist in scope, equality, and transparency when engaging these stakeholders. Few studies have examined the detailed coordination among multi-stakeholders and the performance of their partnerships, creating an opportunity to understand how multi-stakeholders contribute to and manage efforts for future adaptation projects. This study focused on a transboundary action research project on climate adaptation, analyzing the partnership structure, stakeholder arrangements, coordination scenarios, and the role of the partnership within it. It included interviews with project personnel and focus group discussions with community members at the project sites. The results showed that the project emphasized collaboration while maintaining both vertical and horizontal coordination. The donor maintained vertical coordination for monitoring but collaborated on budget adjustments, funding, identifying challenges, and developing strategies to improve the partnership. Partners continued horizontal coordination by sharing responsibilities and taking leadership roles in synthesizing research reports. Additionally, this project facilitated community participation in piloting the adaptation intervention. Although this partnership aimed to establish collaboration, it remains far from effectively liaising with national-level governments to maximize the benefits of adaptation technology. Future research should expand this scope to promote sustainable development. Full article

The combined effect of sulfate-reducing bacteria (SRB) and a microstructure on the stress corrosion behavior of heat-affected zones (HAZs) in pipeline steel for shale gas field applications was investigated. The results show that when the peak heating temperature reached 1020 °C, a coarse microstructure formed during multiple thermal cycles (MTCs), and Widmanstätten structures appeared in the HAZ. In the simulated environment, SRB intensified localized pitting corrosion of both the base metal and the HAZ. The welding HAZ was softened by the MTCs, and significant microcrack growth was observed in the presence of SRB. Among all subzones, the coarse-grained HAZ (CGHAZ) was the most susceptible to stress corrosion cracking (SCC) under shale gas service conditions. Cracks initiated at the metal surface and propagated vertically into the material. SRB activity further increased the SCC sensitivity of the CGHAZ. Full article

In lateral-joint-widening projects of multi-span continuous concrete box girder bridges, significant discrepancies in longitudinal shrinkage, creep deformation, and vertical displacement between the existing and newly added bridge sections can lead to stress concentration and subsequent concrete cracking. Notably, such incompatibility often results in pronounced overall lateral bending deformation, which compromises the structural safety and service reliability of the widened bridge. To address these challenges, this study proposes a novel sliding-type transverse connection structure. This innovative connection enables the independent development of longitudinal shrinkage and creep deformation in the new bridge superstructure relative to the old one through a sliding mechanism, thereby effectively mitigating stress concentration and minimizing overall bending deformation caused by differential deformations. To validate the feasibility and elucidate the load transfer mechanism of the proposed structure, both scaled model tests and finite element simulations were conducted. The results indicate that the connection not only effectively coordinates longitudinal deformation differences and accommodates vertical deformation between the flange plates of the new and old bridges, but also ensures efficient transverse load transfer through shear force transmission. The structural behavior is primarily governed by shear stress distribution. These findings demonstrate that the sliding-type transverse connection significantly improves deformation compatibility in bridge widening applications, thereby enhancing the mechanical performance and safety reliability of the overall structure. Full article

Societal challenges are inherently complex and multi-tiered, arising from the interplay of diverse stakeholders with a spectrum of purposes and different perceptions and expectations, interdependent systems, and dynamic contextual factors that transcend single domains or disciplines. This paper presents a novel approach to developing a Reference Model of Governance tailored to a specific complex, multi-organisational enterprise facing socially complex challenges. Drawing on Angyal’s systems framework, the model introduces a three-dimensional structure with vertical, progression, and transverse dimensions, integrated within a holistic contextual whole. By mapping selected systems methodologies, including Soft Systems Methodology (SSM), Viable System Model (VSM), System Dynamics (SD), and dependency modelling, to these dimensions, the model offers a pragmatic, structured way to explore and regulate complex organisational behaviour. It enables collaborative inquiry, supports adaptive governance, and enhances the enterprise’s ability to address dynamic societal problems such as health, education, and public service delivery. The result is a governance reference model that captures both the operational and contextual realities of the enterprise, providing actionable insight for strategic design or diagnostic intervention. The novel approach is grounded in systemic and critical systems thinking and emphasises the use of methods for understanding to develop a common and shared understanding of the enterprise context and to surface multiple stakeholder perspectives. Full article

Vertical alliances within agricultural supply chains serve as critical institutional vehicles for deepening triple-sector integration (primary–secondary–tertiary) in rural economies, driving agricultural modernization, and advancing rural revitalization. However, sustaining alliance stability constitutes a complex dynamic process wherein inadequate stakeholder engagement and collaborative failures frequently precipitate alliance instability or even dissolution. Existing scholarship exhibits limited systematic examination of the micro-mechanisms and regulatory pathways through which multi-agent strategic interactions affect alliance stability from a dynamic evolutionary perspective. To address this gap, this research focuses on China’s core agricultural innovation vehicle—the Agricultural Industrialization Consortium—and examines the tripartite structure of “Leading Enterprise–Family Farm–Integrated Agricultural Service Providers.” We construct a tripartite evolutionary game model to systematically analyze (1) the influence mechanisms governing cooperative strategy selection, and (2) the regulatory effects of key parameters on consortium stability through strategic stability analysis and multi-scenario simulations. Our key findings are as follows: Four strategic equilibrium scenarios emerge under specific conditions, with synergistic parameter optimization constituting the fundamental driver of alliance stability. Specific mechanisms are as follows: (i) compensation mechanisms effectively mobilize leading enterprises under widespread defection, though excessive penalties erode reciprocity principles; (ii) strategic reductions in benefit sharing ratios coupled with moderate factor value-added coefficients are critical for reversing leading enterprises’ defection; (iii) dual adjustment of cost sharing and benefit sharing coefficients is necessary to resolve bilateral defection dilemmas; and (iv) synchronized optimization of compensation, cost sharing, benefit sharing, and value-added parameters represents the sole pathway to achieving stable (1,1,1) full-cooperation equilibrium. Critical barriers include threshold effects in benefit sharing ratios (defection triggers when shared benefits > cooperative benefits) and the inherent trade-off between penalty intensity and alliance resilience. Consequently, policy interventions must balance immediate constraints with long-term cooperative sustainability. This study extends the application of evolutionary game theory in agricultural organization research by revealing the micro-level mechanisms underlying alliance stability and providing a novel analytical framework for addressing the ‘strategy–equilibrium’ paradox in multi-agent cooperation. Our work not only offers new theoretical perspectives and methodological support for understanding the dynamic stability mechanisms of agricultural vertical alliances but also establishes a substantive theoretical foundation for optimizing consortium governance and promoting long-term alliance stability. Full article

Introduction: Eliminating mother-to-child transmission (EMTCT) of HIV is a global health priority to ensure that no child is born with HIV. When EMTCT services are underutilized, mothers and babies face greater risks, including the vertical transmission of HIV and higher rates of maternal and neonatal mortality. Despite ongoing efforts, many women worldwide still struggle to access and use these vital services. Objective: This study sought to explore barriers and facilitators to the elimination of mother-to-child transmission services among pregnant and breastfeeding women (PBFW) in Gauteng province, South Africa. Methods: A qualitative, explorative, and descriptive research design was used. Convenience and purposive sampling were used to select participants. The study population consisted of PBFW aged 18 years or above who were utilizing EMTCT services. Data was collected through in-depth face-to-face individual interviews with participants. A semi-structured interview guide was used to collect data until data saturation was reached after interviewing 25 participants. Data were analyzed using thematic analysis (Tesch’s open coding method). Trustworthiness and ethical principles were ensured. Results: Four main themes emerged from the data analyzed, namely, barriers associated with EMTCT service utilization, facility-based strategies to improve EMTCT service uptake, community support for enhancing EMTCT engagement, and the role of partner support in service utilization, each with linked sub-themes. This study found that health education about EMTCT, along with community awareness and involvement, encourages the target group to utilize these services. Conclusions: Increasing women’s use of EMTCT services is an important step toward eliminating MTCT and increasing the health and well-being of mothers and their children. Addressing numerous barriers to receiving these services, as well as implementing targeted measures, can help ensure that all women gain access to the care and support that they require to safeguard their families from HIV. Full article