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Inefficiencies in traditional spare parts management for aircraft maintenance—including excessive inventory costs, supply chain delays, and operational disruptions—have long hindered fleet readiness and increased maintenance expenditure. To address these challenges, an integrated, reliability-driven inventory optimization framework has been developed by leveraging predictive analytics, real-time sensor data, and emerging digital technologies. The proposed model is grounded in Reliability-Centered Maintenance (RCM) principles and enhanced by Artificial Intelligence (AI), the Internet of Things (IoT), and digital twin technologies. Through the deployment of advanced sensor networks, real-time performance data are continuously collected and analyzed to forecast component degradation and predict imminent failures. This enables the transition from time-based to condition-based maintenance scheduling. Predictive models, including Long Short-Term Memory (LSTM) neural networks and Random Forest classifiers, are employed to enhance the accuracy of failure prognostics and spare parts demand forecasting. The dynamic alignment of spare parts provisioning with actual equipment reliability has been shown to reduce overstocking and prevent critical shortages. A case study conducted within a commercial airline fleet demonstrated a 20% reduction in inventory-related costs and a 15% decrease in aircraft downtime. Furthermore, operational efficiency and safety were significantly improved by minimizing unscheduled maintenance events. The proposed framework not only supports predictive and prescriptive maintenance strategies but also establishes a replicable model for digital transformation in aviation logistics. By integrating real-time analytics with digital twin simulations, a data-centric paradigm is introduced for proactive maintenance decision-making. This advancement paves the way towards more sustainable, cost-effective, and resilient aviation operations, aligning with broader industry goals of environmental responsibility and performance optimization.

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Green supplier selection (GSS) as a critical strategic element is placed in the limelight in contemporary supply chain management (SCM), owing to the growing emphasis on environmental responsibility and sustainability. This study presents a fuzzy multi-criteria decision-making (FMCDM) framework, employing Fuzzy Logarithmic Percentage Change-Driven Objective Weighting (FLOPCOW) method to determine the relative importance of sustainability criteria under uncertainty. A panel of five academic and industry experts was selected to identify 21 criteria, which were categorized into three main dimensions including environmental performance (C1), resource efficiency (C2), and corporate sustainability policies (C3). Triangular fuzzy numbers (TFNs) were adopted to model linguistic ambiguities in expert judgments whereas fuzzy normalization was applied to ascertain the weights of criteria. Key findings indicated that corporate sustainability policies (C3) were prioritized as the most influential dimension, followed by environmental performance (C1) and resource efficiency (C2). This suggested the centrality of institutional governance in advancing long-term sustainability objectives. Sub-criteria analysis further revealed ecological training programs, air emissions control, and sustainability reporting as the most critical indicators in the interplay of operational practices and transparent governance. FLOPCOW has effectively processed expert opinions with the use of fuzzy normalization, hence advocating a clear and repeatable approach for the evaluation of green suppliers. Furthermore, it highlighted the importance of policy-based criteria in supplier assessment and organizations could then align their purchasing decisions with sustainability goals by considering more on governance-related factors like compliance and stakeholder engagement.

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The problem of job scheduling in parallel machine environments, where both processing times and setup times are characterized by stochastic variability, has been investigated with a focus on enhancing the efficiency of resource allocation in complex production systems. Job scheduling, as a critical component of operations research and systems engineering, plays a vital role in the optimization of large-scale, flexible manufacturing and service environments. In this study, a stochastic scheduling model has been formulated to minimize the maximum completion time (denoted as $Ct_{\textit{max}}$), under the simultaneous influence of probabilistic job durations and setup times associated with tool preparation. The problem has been addressed using two prominent metaheuristic algorithms: Genetic Algorithm (GA) and Simulated Annealing (SA). These methods were selected due to their demonstrated capacity to navigate large, non-deterministic search spaces efficiently and their adaptability to multi-constraint scheduling problems. A comparative analysis has been conducted by applying both algorithms under identical initial conditions, with algorithmic performance evaluated in terms of solution quality, computational efficiency, and robustness to input variability. The model incorporates key practical considerations, including randomized setup times which are often neglected in conventional deterministic scheduling models, thereby improving its relevance to real-world industrial settings. The formulation of the problem allows for additional constraints and objectives to be flexibly integrated in future research, including resource conflicts, machine eligibility constraints, and energy-aware scheduling. Empirical results suggest that while both algorithms are effective in deriving near-optimal schedules, notable differences exist in convergence behavior and sensitivity to parameter tuning. The findings offer critical insights into the comparative strengths of GA and SA in managing the stochastic nature of parallel machine scheduling problems. By advancing a robust metaheuristic framework that accounts for real-world uncertainties, this study contributes to the ongoing development of intelligent scheduling systems in systems engineering, manufacturing logistics, and automated production planning.

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It is crucial to ensure system reliability in changing situations where systems are required to operate in uncertainty or against disturbances. Human-in-the-Loop (HITL) simulations have in recent times emerged as an important key in ensuring the robustness and resilience of the system via evaluation and testing. The method introduces human decision-making and adaptability as well as providing insight into zones of possible weak points of the system and failure modes which are not even captured by computer-based systems. By incorporating HITL simulations into the system, designers and engineers could simulate operational challenges in real life, identify unforeseen defects, and implement mitigative strategies to enhance both robustness-ensuring consistent performance in the nominal operation and resilience-maintaining functionality in and after disruptions. This article looks at the effectiveness of HITL simulations in various domains, and particularly at the role that these contribute to system robustness and resilience. Among the most significant issues will be the nature of building the simulation environments, the test for the range of scenarios, and the roles for humans to be simulated within the loop. We investigate the behavior of humans during stress and uncertainty, then provide valuable feedback to the system to help it learn. By revealing the vulnerabilities of the system design and acknowledging human effects on recovery and decision-making operations, HITL simulations finalize the development of more adaptable, stable systems that could recover rapidly from interruptions. To conclude, HITL simulations are a critical tool for improving the reliability of systems, hence providing a comprehensive framework to address either expected or unexpected challenges in complex operating environments.

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This study presents a comprehensive comparison of modern cementitious composites, including UHPC, ECC, and GFRC, with traditional Ordinary Portland Cement (OPC) and ancient Opus Caementicium (Roman). Emphasis is placed on mechanical, physical, and rheological properties, as well as environmental and durability aspects. Advanced composites demonstrate superior short-termmechanical performance and improved impermeability, while Roman binders exhibit unparalleled long-term resilience in marine environments. Furthermore, the integration of pozzolanic materials and industrial by-products in contemporary mixes highlights ongoing efforts toward sustainable construction. Recent developments in China, including metakaolin–slag blends and nano-silica additives, as well as bio-inspired self-healing approaches, illustrate promising pathways for reducing carbon footprint and enhancing durability.

Open Access
Research article
The Influence of Climate Literacy and Awareness on the Utilisation of Climate-Related Information among Unskilled Construction Workers in Malaysia
isyaku hassan ,
mohd nazri latiff azmi ,
muhamad fazil ahmad ,
qaribu yahaya nasidi ,
ahmad taufik hidayah abdullah
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Available online: 07-22-2025

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Substantial scientific consensus has confirmed that global warming, driven by climate change, poses significant risks to both environmental and occupational systems. In response, the Malaysian government has taken notable steps, including the enactment of the National Policy on Climate Change in 2009 and subsequent commitments to develop comprehensive legislation aimed at strengthening national climate strategies. Despite these institutional efforts, the dissemination and uptake of climate-related information remain hindered by misinformation campaigns and varying levels of public literacy. Among those most vulnerable are unskilled construction workers, who are increasingly exposed to occupational hazards, productivity disruptions, and worksite risks linked to extreme weather events. To evaluate how climate literacy and awareness influence the utilisation of climate-related information within this group, a cross-sectional study was conducted involving 144 randomly selected unskilled construction workers registered with the Construction Industry Development Board (CIDB) across the Malaysian states of Terengganu and Selangor. Data were collected using structured, self-administered questionnaires and analysed through structural equation modelling using analysis of moment Structures (SEM-AMOS). The results revealed that higher levels of climate literacy significantly enhanced the effective use of climate-related information, whereas general awareness of climate change did not demonstrate a statistically significant effect. This divergence indicates that while awareness may foster recognition of climate issues, it is the depth of literacy—defined as the ability to critically interpret, evaluate, and act upon climate information—that drives meaningful behavioural engagement. These findings underscore the necessity for policy frameworks and educational interventions to prioritise literacy-building rather than awareness campaigns alone. It is proposed that targeted capacity-building programmes, particularly within labour-intensive industries, be developed to equip vulnerable populations with the necessary tools for informed decision-making in climate-sensitive contexts. This study advances the academic discourse on climate communication and policy implementation by identifying literacy as a pivotal factor in climate information engagement among marginalised labour segments.

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This study presented a novel mathematical functional-based algorithm designed to predict the risks of vehicular crashes by leveraging real-time traffic data collected from urban road networks. The proposed model integrated multiple critical variables, including traffic speed, vehicle density, visibility conditions, spatial coordinates, and time-of-day factors, to generate a comprehensive and dynamic assessment for foreseeing the likelihood of traffic crashes. The flexible functional framework enabled the incorporation of diverse traffic and environmental variables, thereby improving the accuracy and contextual sensitivity of risk predictions for road traffic. The model was calibrated and validated using real-world traffic data from five key locations in Islamabad, Pakistan, known for their varying traffic patterns. The results demonstrated that the model could effectively identify high-risk zones and specific time intervals during the day when the probability of crashes was elevated. For example, areas such as Inter-junction Principal (IJP) Road exhibited significantly higher risks of crashes during peak congestion hours, correlating strongly with increased vehicle density and reduced visibility. The study highlighted the potential of combining mathematical modeling with real-time data analytics to address the growing challenges of traffic safety in rapidly urbanizing cities. By providing spatially and temporally resolved estimations of risks, the proposed method enables urban planners and traffic authorities to implement proactive and targeted safety interventions, such as dynamic traffic signaling, speed regulation, and public awareness campaigns. This approach not only enhances urban traffic management but also contributes to reducing accident rates and improving overall road safety.

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In modern foundry operations, the reliability and operational continuity of sand molding systems are pivotal to maintaining productivity, safety, and competitive advantage. In this study, Failure Mode, Effects, and Criticality Analysis (FMECA) has been employed to systematically evaluate and optimize the performance of a pneumatic molding cell utilized in the production of sand molds. Particular focus has been directed toward the pusher subsystem, which is frequently subjected to high mechanical loads and cyclic stress, rendering it susceptible to recurrent failures that compromise both uptime and process efficiency. Potential failure modes were exhaustively identified, categorized, and prioritized based on their severity, occurrence, and detectability. Critical components, including servo motors, pneumatic actuators, and gearbox assemblies, were found to pose substantial risk to system reliability due to wear-induced degradation, misalignment, and lubrication failure. For each high-priority failure mode, targeted mitigation strategies were proposed, encompassing enhanced condition monitoring, retrofitting of wear-resistant materials, and redesign of high-stress interfaces. Furthermore, failure detection mechanisms were improved through the integration of predictive maintenance protocols and sensor-based diagnostics. Implementation of these recommendations has resulted in measurable reductions in unplanned downtime, repair frequency, and maintenance overhead. This investigation demonstrates that FMECA, though underutilized in conventional foundry environments, offers a structured, data-driven methodology for uncovering latent failure risks and implementing preventive measures in complex industrial systems. By embedding FMECA within routine maintenance frameworks, a substantial improvement in operational resilience and equipment lifespan can be achieved. The findings support the strategic integration of reliability engineering methodologies into sand molding operations, contributing not only to cost efficiency but also to the broader adoption of systematic risk management practices in process-driven manufacturing sectors.

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Reliable detection of road surface objects under foggy conditions remains a critical challenge for autonomous vehicle perception systems due to the severe degradation of visual information. To address this limitation, a novel framework was developed that integrates entropy-guided visibility enhancement, Pythagorean fuzzy logic, and structure-preserving saliency modeling to improve object detection performance in low-visibility environments. Visibility restoration was achieved through an entropy-guided weighting mechanism that selectively enhances salient image regions while preserving essential structural features critical for downstream detection tasks. Uncertainty and imprecision inherent to fog-degraded scenes were systematically modeled using Pythagorean fuzzy logic, enabling improved confidence estimation and robustness in object localization. A saliency mechanism that preserves structural characteristics further contributes to the accurate delineation of road-relevant elements. Extensive evaluations on multiple publicly available foggy road datasets were conducted, demonstrating substantial gains in detection performance, with notable improvements in accuracy, precision, recall, and F1-score metrics. Furthermore, enhancements in visual quality were verified using structural similarity index (SSIM), peak signal-to-noise ratio (PSNR), natural image quality evaluator (NIQE), and blind/referenceless image spatial quality evaluator (BRISQUE) metrics. The computational efficiency of the proposed method was confirmed, supporting its applicability to near real-time deployment scenarios. Consistent performance was observed across varying fog densities, highlighting the framework’s scalability and generalizability. The integration of entropy-based visibility enhancement with fuzzy reasoning and saliency preservation offers a comprehensive and practical solution to the challenges of perception in visually degraded environments, contributing to the advancement of safe and intelligent transportation systems.
Open Access
Research article
Integrated Wastewater Management for Environmental Protection and Sustainable Ecotourism in an Andean Paramo Community
bethy merchán-sanmartín ,
belén álava-zúñiga ,
fanny vallejo-palomeque ,
sebastián suárez-zamora ,
maribel aguilar-aguilar ,
fernando morante-carballo
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Available online: 07-10-2025

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The rural Andean community of Yacubiana, Ecuador, currently lacks an adequate sanitation infrastructure, with domestic wastewater managed through individual septic tanks. These decentralized systems have exhibited significant infiltration issues, resulting in groundwater contamination, degradation of sensitive páramo ecosystems, and adverse public health outcomes. Furthermore, this environmental degradation has impeded the community’s potential for ecotourism-based development. To address these challenges, an integrated wastewater management strategy was developed, grounded in sanitary engineering principles and aligned with conservation priorities. The proposed framework encompassed four sequential phases: (i) a comprehensive analysis of existing data on water and wastewater practices within the community; (ii) a systematic evaluation of sanitation alternatives tailored to the community’s socio-environmental context and the ecological fragility of Andean paramos; (iii) the design of a selected sanitation solution in accordance with national and international technical standards; and (iv) a SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis conducted with both technical experts in water resource management and local community representatives. This participatory evaluation aimed to identify strategic pathways for enhancing environmental stewardship, promoting circular water economies, and enabling sustainable tourism. The recommended intervention consists of a simplified, decentralized sewage collection system linked to a trickling filter-based treatment plant, designed for a hydraulic load of 2.79 L/s. The SWOT analysis revealed substantial institutional and infrastructural constraints, primarily due to limited governmental support; however, it also identified considerable ecotourism potential grounded in the area’s geological, ecological, and cultural assets. When implemented within a conservation-based framework, the proposed system is expected to support compliance with Sustainable Development Goals (SDGs) 3 (Good Health and Well-being), 6 (Clean Water and Sanitation), and 11 (Sustainable Cities and Communities). The methodological approach developed herein offers a replicable model for integrated wastewater management in rural, environmentally sensitive regions, providing a viable foundation for community-led, sustainable socio-economic development.

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To facilitate a rigorous evaluation of damage progression in in-service steel frame structures subjected to seismic loading, a seismic damage model that integrates the effects of atmospheric corrosion has been developed. Corrosion-induced deterioration significantly influences the structural integrity of bolted steel frames, yet its impact on seismic performance remains inadequately quantified. In this study, a performance-based seismic damage assessment framework has been established, wherein corrosion-related degradation is incorporated into the structural damage evolution process. Drawing on an extensive review of domestic and international research, a refined damage index classification system has been formulated to characterize varying levels of structural impairment. To validate the proposed model, a seismic collapse simulation was conducted on a 1:4 scaled-down steel frame specimen, enabling a comprehensive analysis of damage accumulation over different service durations. The results confirm that the developed model accurately captures the progressive deterioration and collapse behavior of corroded steel frames under seismic excitation. This study provides a quantitative basis for assessing the post-earthquake residual load-bearing capacity of in-service bolted steel frame structures, offering critical insights for structural resilience evaluation and maintenance planning.
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