Search Results (21,841)

This paper addresses the problem of robust identification of gross errors affecting both measurements and network parameters in power system state estimation. The study is conducted within a steady-state framework and focuses on improving bad data identification in the presence of modeling and measurement uncertainties, explicitly accounting for the limited observability of gross errors. Building on an Extended Weighted Least Squares (EWLS) estimator and a theoretically refined eigenvalue-based clustering of dominant error components, a novel Bayesian identification framework is introduced. The proposed Bayesian approach assigns probabilities to competing gross error models, including scenarios involving multiple simultaneous errors, given the observed clusters of dominant errors. This probabilistic formulation enables a systematic and quantitative decision-making process for identifying the most likely sources of gross errors, extending existing deterministic or heuristic approaches. The methodology is evaluated through numerical simulations on the IEEE-14 bus test system, considering several gross error scenarios and significant parameter uncertainties. The results demonstrate that the proposed Bayesian framework enhances the interpretability and discriminative capability of gross error identification, highlighting its potential for robust bad data identification in power system state estimation. Full article

In the age of remote communication and digital archiving, automated analysis of voice data has become increasingly important in various application areas. Despite significant advances in the field of Automatic Speech Recognition, integrating speaker recognition, textual sentiment analysis, and acoustic sentiment detection within a unified real-time processing pipeline remains a challenging task. Current approaches are often limited to monolithic designs or operate in batch processing modes, which restricts their scalability and real-time applicability. To address this gap, this work proposes a novel feature selection method called RAM, along with a hybrid decision-level merging approach combining Conv1D CNN and AutoML-based models. The proposed hybrid framework enables independent model training and integrates its probabilistic outputs through a weighted merging strategy for performance improvement. Furthermore, a scalable microservice-based software architecture has been developed to support real-time processing, feature selection, and model deployment. This design enhances system modularity, flexibility, and integration capability in practical applications. Experimental results show that when the proposed RAM method is used in conjunction with a hybrid AI model, it achieves over 97% accuracy in speaker recognition and over 82% accuracy in emotion classification, even with short audio samples. These findings demonstrate that the proposed approach provides a robust and efficient solution for real-time speech analysis tasks. Full article

This paper investigates the cooperative formation control problem in unmanned surface vehicles (USVs) with prescribed performance constraints under complex marine conditions including external disturbances, model uncertainties, actuator faults, and input saturation. A novel fault-tolerant control (FTC) algorithm is developed by integrating cooperative learning neural networks (NNs), distributed disturbance observers, and the backstepping technique. Specifically, the learning NNs adaptively approximate system uncertainties, and the learned weight information is shared among vehicles to enhance cooperative cognition. Additionally, an auxiliary dynamic system and an actuator configuration matrix are designed to compensate for input saturation and propeller failures. Theoretical analysis based on the Lyapunov method proves that all signals in the closed-loop system are bounded, and the formation tracking errors strictly remain within the predefined transient and steady-state performance bounds. Finally, simulation experiments involving a group of four USVs validate the proposed algorithm. The results demonstrate that the USVs can rapidly converge to and maintain the desired quadrilateral formation shape despite time-varying disturbances and actuator efficiency loss. Furthermore, comparative simulation results indicate that the proposed cooperative learning FTC scheme significantly reduces velocity tracking error oscillations compared to traditional non-learning methods, explicitly verifying its superior robustness and fault-tolerant capabilities. Full article

To meet the high-fidelity testing environment requirements for autonomous driving system development, driving simulators are gradually evolving from tools that “only provide scenes and interaction interfaces” into integrated verification platforms for autonomous driving capabilities. These simulators, in particular, need to feature testable and scalable decision-making modules. However, the autonomous driving functions in existing driving simulators mostly rely on rule-based or simplified model approaches, which are inadequate for depicting the complex interactions in real-world traffic and fail to meet the personalized decision-making needs under various driving styles. To address these challenges, this paper designs and implements a trajectory data-driven personalized autonomous driving decision system, using drone aerial imagery as the core data source to provide realistic background traffic flow and human-like decision-making capabilities. The proposed system can be interpreted as an integrated decision–planning–control framework deployed within a high-fidelity driving simulation platform. It consists of a driving style classification module based on drone trajectory data, a personalized decision module integrating inverse reinforcement learning and dynamic game theory, and a planning and control module. First, a natural driving database is built using 4997 real vehicle trajectories, and prior features of different driving styles are extracted through trajectory feature engineering and an improved K-means++ method. Based on this, a personalized decision-making framework that combines dynamic game theory and maximum entropy inverse reinforcement learning is proposed, aiming to learn the preference weights of different driving styles in terms of safety, comfort, and efficiency. Furthermore, the Dueling Network Architecture (DuDQN) is used to generate human-like lane-changing strategies. Subsequently, a real-time closed-loop execution of personalized decisions in the simulation platform is achieved through fifth-order polynomial trajectory planning, lateral Linear Quadratic Regulator (LQR) control, and longitudinal cascade Proportional–Integral–Derivative (PID) control. Experimental results show that the personalized decision model trained with drone data can realistically reproduce vehicle decision-making behaviors in natural traffic flows within the simulation environment and generate autonomous driving strategies that are highly consistent with different driving styles. This significantly enhances the humanization and personalization capabilities of the autonomous driving module in the driving simulator. Full article

Corrosion continues to be a major concern in industrial systems, causing material degradation and raising maintenance costs. In recent years, plant-derived corrosion inhibitors have gained interest as environmentally friendly alternatives to conventional chemical treatments. In this work, ethanolic extracts from the leaves of Citrus limon (L.) Osbeck and Eucalyptus globulus Labill. were evaluated as green corrosion inhibitors for C45 carbon steel in 1 M HCl solution. The extracts were prepared by continuous Soxhlet extraction and characterized through antioxidant activity measurements using the 2,2-diphenyl-1-picrylhydrazyl DPPH radical scavenging method, gravimetric (weight loss) tests, and electrochemical techniques including potentiodynamic polarization. In addition, the extraction parameters were optimized using a face-centered central composite design (CCD) within a response surface methodology (RSM) framework, and the resulting models were analyzed by analysis of variance (ANOVA). The effects of inhibitor concentration and temperature on corrosion inhibition performance were systematically examined. The antioxidant assay indicated that E. globulus extract reached a scavenging activity above 95% at 1000 mg/L, while C. limon extract showed moderate activity around 71%. Gravimetric tests revealed that both extracts reduced the corrosion rate, with optimal inhibition efficiencies of approximately 67% for C. limon (at 0.3 g/100 mL) and 82% for E. globulus (at 1.0 g/100 mL). Beyond these optimal concentrations, a decline in performance was observed, suggesting surface saturation. The statistical optimization showed that the C. limon response model was solvent-driven (R² = 92.05%), whereas the E. globulus model was curvature-driven (R² = 95.45%), with contrasting response surface topographies. Electrochemical measurements confirmed that both extracts acted as mixed-type inhibitors, shifting the corrosion potential toward less negative values and reducing the corrosion current density. Overall, E. globulus extract demonstrated superior performance across all methods, and both extracts represent promising candidates for sustainable corrosion protection in acidic industrial environments. Full article

Cultivated land fragmentation has become a critical constraint on regional agricultural sustainable development. Revealing its spatial patterns and driving mechanisms is of great significance for optimizing the utilization and management of cultivated land resources and enhancing regional agricultural productivity. This study focuses on the main grain-producing areas in the middle and lower reaches of the Yangtze River Basin. It constructs a Cultivated Land Fragmentation Index (CLFI) using an integrated method that combines landscape index analysis with an entropy-weighted approach, based on 2023 land-use data. The optimal analytical grain size and extent were determined before employing geographic detectors to identify dominant factors influencing cultivated land fragmentation. The key findings include the following: (1) The appropriate spatial resolution for fragmentation analysis was identified as 330 m, with an optimal analysis extent of 8910 m. (2) CLFI values ranged from 0.001 to 0.973, exhibiting significant spatial heterogeneity. The central plains and northeastern regions demonstrated low fragmentation levels and better contiguous cultivated land distribution, while the western and peripheral areas showed higher fragmentation. A provincial-scale comparison revealed that Jiangxi Province had the highest fragmentation level (0.255), whereas Jiangsu Province had the lowest (0.146). The topographic gradient analysis indicated a decreasing trend from the Guizhou Plateau (0.503) to the North China Plain (0.125), with plateaus and basins showing significantly higher fragmentation than hilly and plain regions. (3) Dominant controlling factors varied among provinces: In provinces with greater topographic relief (Anhui, Hubei, Hunan, Jiangxi), natural factors like elevation, slope gradient, and NDVI primarily controlled fragmentation patterns; in contrast, socioeconomic factors such as nighttime light intensity dominated in Jiangsu Province, characterized by flat terrain and high urbanization. Multi-factor interactions generally enhanced explanatory power regarding spatial patterns, confirming that cultivated land fragmentation is a result of comprehensive multi-factor interactions. This study reveals the spatial distribution characteristics of cultivated land fragmentation at the pixel scale in the study region, providing theoretical foundations and decision-making references for the efficient utilization of cultivated land resources and rural land system reforms. Full article

Surface discharge-induced degradation poses a significant threat to the operational reliability of high-voltage insulation systems. This research investigates the dielectric endurance of polyester-based nanocomposites reinforced with seven distinct nano-additives: iron oxide (Fe₃O₄), copper oxide (CuO), titanium oxide (TiO₂), aluminum oxide (Al₂O₃), silicon dioxide (SiO₂), zinc borate (ZnB) and graphene oxide (GO). Specimens were fabricated at 0.5% and 0.75% weight concentrations and subjected to constant AC electrical stress of 4.5 kV at 50 Hz until failure using the first-plane tracking method. To accurately monitor the aging process, a sophisticated signal processing framework involving Hankel-matrix-enhanced Robust Principal Component Analysis (RPCA) was developed to extract high-frequency discharge features from captured leakage current signals. The degradation characteristics were quantified using various statistical metrics, including Kurtosis, RMS and Burst Discharge Index (BDI). Experimental findings demonstrate that the incorporation of nanoparticles significantly extends the time-to-failure compared to neat polyester, although the effectiveness is highly dependent on both additive type and concentration. At 0.5 wt.%, ZnB exhibited the superior performance in delaying carbonized track formation. However, at 0.75 wt.%, Al₂O₃ emerged as the most effective additive, achieving a maximum endurance time of 31.61 min. In contrast, certain additives like TiO₂ showed a performance decline at higher loadings, likely due to nanoparticle agglomeration. The Hankel-RPCA methodology successfully isolated discharge-specific signatures from background noise, establishing a strong correlation between signal features and material failure stages. This study confirms that the synergy between advanced nanomaterial modification and robust signal processing provides an effective diagnostic tool for monitoring insulation health, offering a vital pathway for the designing of high-performance dielectrics for real-world power system applications. Full article

This study investigates the synergistic effects between High-quality Urban Economic Development (HUED) and Integrated Urban–Rural Development (IURD) in Zhejiang Province (2014–2023). The research methodology incorporates the entropy weighting technique, the coupling coordination degree (CCD) model, and the relative development evaluation model. The results show that: (1) The two systems exhibit asynchronous evolution—HUED shows a slight downward trend, whereas IURD increases by 35.94%. (2) The mean CCD rises from 0.596 to 0.633, indicating a transition to moderate coordination, with a distinct “high north, low south” spatial pattern. (3) The spatial integration subsystem shows the lowest coordination with urban economic development, representing a key structural constraint. (4) Ten coupling coordination types are identified, among which “moderate coordination with slight lag in economic quality” is the most dominant. Overall, Zhejiang’s urban–rural relationship faces dual constraints: insufficient spatial integration at the subsystem level and lagged high-quality economic development at the system level. Accordingly, targeted spatial optimization and place-based policies are proposed. Full article

Vulnerabilities in conventional agri-food supply chains (CAFSCs) necessitate a shift toward resilient, localized production models. Within the Agri-Food 4.0 landscape, urban Controlled-Environment Hydroponic Agriculture (CEHA) systems address these challenges by shortening supply chains and mitigating climate-induced breakdowns. However, structurally aligning Triple Bottom Line (TBL)-oriented stakeholder needs with complex technical specifications remains a critical challenge in sustainable CEHA system design. To address this challenge, the present study proposes a novel framework integrating the Full Consistency Method (FUCOM) and Quality Function Deployment (QFD) within a Finite Interval Type-2 (FIT2) Gaussian fuzzy environment. This approach systematically translates TBL-oriented priorities into precise engineering specifications, mapping 17 stakeholder needs (SNs) to 30 technical design requirements (TDRs) while capturing linguistic uncertainty and hesitation. The findings reveal a clear strategic focus on environmental and social sustainability. Specifically, high product quality, food safety and traceability, consumer acceptance, and minimization of environmental impacts emerge as the primary drivers of CEHA adoption. The QFD translation identifies scalable IoT infrastructure, sensor maintenance and calibration, and AI-enabled decision support as the most critical TDRs. The framework’s reliability and structural robustness were rigorously validated through comprehensive analyses, including Kendall’s W test to confirm expert consensus, alongside a Leave-One-Out (LOO) approach, weight perturbations, and a structural evaluation of TDR intercorrelations. These findings provide a scientifically grounded roadmap for designing sustainable, intelligent urban agricultural systems. Ultimately, this framework offers actionable managerial implications for agribusiness stakeholders to bridge strategic TBL-oriented goals with practical engineering, significantly enhancing Agri-Food 4.0 supply chain resilience. Full article

Background/Objectives: Traumatic spinal fractures are common injuries, and a proportion of these cases require surgical stabilization using various operative systems. This study aimed to analyze the epidemiology of surgical site infections (SSIs) following exclusively trauma-related spinal surgery and to identify potential risk factors for their occurrence, as there is a lack of studies focusing on non-elective trauma-related spinal surgeries and SSI in the literature. Methods: This retrospective single-center analysis examined 710 patients with traumatic spinal injuries treated surgically between 2012 and 2022 at the Level I Trauma Center at the Department of Orthopedics and Trauma Surgery of the University Hospital Wiener Neustadt, Austria. To investigate SSI risk factors, comparative statistical analyses and logistic regression were used, with a level of statistical significance of α = 0.05. Results: In total, 28 cases (with an incidence of 3.94%) developed SSI, and these cases were characterized by a significantly higher body weight/BMI, longer operative times, and more stabilized segments and implanted hardware. They were also more likely to have undergone open surgery, laminectomy in combination with dorsal stabilization, intensive care treatment, or to present with neurological deficits or ankylosing spondylitis. SSIs occurred most frequently in the thoracolumbar and cervicothoracic junctions, and were predominantly caused by Staphylococcus epidermidis, Staphylococcus aureus, and Cutibacterium acnes. As independent risk factors, a higher BMI (OR = 1.188) and the use of cross-connectors (OR = 4.948) were identified, whereas other initially significant variables did not remain significant after adjustment. Conclusions: There are surgery-related and potentially modifiable variables and non-modifiable patient-related risk factors for the occurrence of SSI. Patients with SSIs stayed an average of 25.3 days in hospital and had a mortality rate of 17.9%. Full article

The rapid growth of large-scale Internet of Things (IoT) deployments in urban environments requires accurate and energy-efficient localization methods for low-power wireless devices. In long-range wide-area networks (LoRaWAN), traditional GPS-based positioning is often impractical due to energy consumption constraints and signal propagation challenges in urban areas. This study proposes a hybrid localization system that integrates weighted centroid localization (WCL) with a machine learning (ML) regression model to improve outdoor positioning accuracy. The proposed approach first estimates approximate transmitter coordinates using a physically grounded WCL method based on received signal strength indicator (RSSI) measurements. These initial estimates are subsequently refined by ML models trained to learn nonlinear residual corrections. In addition to random partitioning, a spatial data splitting strategy is proposed and evaluated using a publicly available LoRaWAN dataset. The experimental results demonstrate that the hybrid WCL framework combined with a multilayer perceptron (MLP) significantly outperforms other ML models. The proposed method achieves a mean localization error of 160.47 m and a median error of 73.78 m. Compared to the baseline model, the integration of WCL reduces the mean localization error by approximately 29%, highlighting the effectiveness of incorporating physically interpretable priors into localization models. Full article

Landscape visual impact assessment is a key component of environmental impact studies, as it enables the identification and management of negative effects on the territory. Traditional methods are often subjective, rely on expert judgement, and consider limited criteria. To address these limitations, this study proposes a quantitative index based on the integration of grey clustering and Shannon entropy complemented with Geographic Information System (GIS). This approach allows classification under uncertainty and the objective weighting of indicators related to physiographic, biotic, and anthropic factors of visual quality, fragility, and accessibility. The methodology was applied to an open-pit mine in Peru. Results show that terrain modifications, presence of artificial elements, and the alteration of water bodies significantly affect visual quality, while the absence of restoration measures, observer exposure, and vegetation type increase fragility and reduce landscape resilience. The proposed method provides a robust, transparent, and reproducible framework that overcomes subjectivity in traditional approaches, supporting more reliable environmental planning and management. Full article

Metabolic dysfunction–associated steatotic liver disease (MASLD) is a systemic metabolic disorder characterized by impaired metabolic flexibility involving the liver, skeletal muscle, and adipose tissue. Although weight loss has traditionally been emphasized in its management, emerging evidence suggests that exercise exerts therapeutic effects beyond body weight reduction. This narrative review aims to examine exercise as a metabolic therapy for MASLD by integrating mechanistic insights and clinical evidence. Exercise improves hepatic steatosis, insulin resistance, mitochondrial function, and inflammatory signaling through interconnected pathways, including activation of AMPK-related signaling, enhanced fatty acid oxidation, and muscle–liver crosstalk mediated by myokines. Importantly, these benefits can occur independently of weight loss, supporting a shift from weight-centered to metabolism-focused treatment strategies. Both aerobic and resistance exercise demonstrate efficacy, with combined approaches providing complementary benefits. In conclusion, exercise should be considered a central therapeutic strategy for MASLD by restoring metabolic flexibility rather than solely promoting weight reduction. Future research should focus on optimizing individualized and sustainable exercise prescriptions to enhance long-term clinical outcomes. Full article

Air pollution caused by fine particulate matter (PM_2.5) poses a serious public health threat in many South Asian megacities where monitoring networks remain limited. Lahore, Pakistan—frequently ranked among the world’s most polluted cities—still lacks reliable short-term PM_2.5 forecasting systems. This study develops a performance-weighted ensemble machine learning framework that integrates satellite observations, meteorological reanalysis data, and ground monitoring measurements to improve daily PM_2.5 prediction. Eleven predictor variables were processed using a unified Google Earth Engine pipeline, including MODIS aerosol optical depth, Sentinel-5P trace gases (CO, NO₂, SO₂), and ERA5 meteorological parameters. Four tree-based machine learning algorithms—Random Forest, XGBoost, LightGBM, and CatBoost—were trained using daily observations from 2019 to 2023. Model evaluation using an independent 2024 dataset showed strong predictive capability, with Random Forest achieving R² = 0.77 (RMSE = 24.75 µg m⁻³), XGBoost R² = 0.76 (RMSE = 26.32 µg m⁻³), CatBoost R² = 0.73 (RMSE = 30.39 µg m⁻³), and LightGBM R² = 0.70 (RMSE = 32.75 µg m⁻³). To further enhance performance, the best models were combined into a weighted ensemble (RF 0.5, XGBoost 0.3, and CatBoost 0.2), which produced the highest validation accuracy (R² = 0.77; RMSE = 23.37 µg m⁻³). Statistical testing using paired t-tests and Diebold–Mariano tests confirmed that the ensemble significantly reduced forecast errors compared with individual models. Feature importance analysis revealed that surface pressure, temperature, CO, and NO₂ were the most influential predictors of PM_2.5 variability. The proposed framework demonstrates that combining satellite data, reanalysis meteorology, and ground observations through ensemble learning can provide accurate and scalable air quality forecasting for data-limited urban environments. Full article

Cloud-based intrusion detection systems (IDSs) increasingly rely on deep learning classifiers to identify malicious traffic; however, this reliance exposes them to adversarial evasion attacks in which adversaries craft near-imperceptible perturbations to bypass detection. Existing defenses based on conventional adversarial training often recover robustness against known perturbation patterns at the cost of degraded detection accuracy on canonical attack categories—a robustness–accuracy trade-off that remains an open challenge in the field. In this paper, we propose GT-CSAT (Game-Theoretic Cost-Sensitive Adversarial Training), a novel defense framework tailored for cloud security environments. GT-CSAT couples an improved Wasserstein GAN with Gradient Penalty (WGAN-GP) threat generator—conditioned on attack semantics to simulate functionally consistent and highly covert traffic variants—with a minimax adversarial training loop governed by a game-theoretic cost-sensitive loss function. The proposed loss function assigns asymmetric misclassification penalties derived from a two-player zero-sum payoff matrix, enabling the detector to maintain vigilance over both novel adversarial variants and well-characterized conventional threats simultaneously. Specifically, misclassifying an adversarially perturbed attack as benign incurs a strictly higher penalty than the symmetric cross-entropy baseline, while the cost weights are dynamically adapted via a Nash equilibrium-inspired update rule during training. We conduct comprehensive experiments on the Cloud Vulnerabilities Dataset (CVD), CICIDS-2017, and UNSW-NB15, which encompass diverse cloud-specific attack scenarios including denial-of-service, port scanning, brute-force, and SQL injection traffic. Under six representative evasion strategies—FGSM, PGD, C&W, BIM, DeepFool, and IDSGAN-style black-box perturbations—GT-CSAT achieves an average robust accuracy of 94.3%, surpassing standard adversarial training by 6.8 percentage points and the undefended baseline by 21.4 percentage points, while preserving clean-traffic detection at 97.1%. These results confirm that the game-theoretic cost structure effectively decouples robustness from accuracy, yielding a Pareto-superior detection profile relative to competing baselines across all evaluated threat models. The source code and experimental configurations have been publicly released to facilitate reproducibility. Full article