Search Results (14,344)

Energy Performance Contracting (EPC) is increasingly used as a financial mechanism to accelerate renewable energy investments in public infrastructure; however, its effectiveness depends not only on technical performance but also on institutional governance arrangements. This study evaluates a 1.71 MWp grid-connected photovoltaic (PV) system implemented under an EPC model at a public university in Türkiye, examining the interaction between operational performance and institutional governance structures. A mixed-methods research design was applied, combining SCADA-based electricity generation data for the 2024–2025 monitoring period with contract analysis and institutional evaluation. The results indicate that the PV system achieved stable electricity production levels and an average performance ratio of approximately 83%, demonstrating reliable operational performance under real operating conditions. Annual electricity generation reached about 2.13 GWh in 2024 and 2.44 GWh in 2025, corresponding to estimated carbon emission reductions of approximately 895 and 1025 tonnes of CO₂, respectively. Despite these technical achievements, the analysis reveals several governance-related challenges, including fragmented institutional responsibilities and limited transparency in monitoring and verification processes. The findings suggest that the effectiveness of EPC mechanisms depends on the integration of technical performance monitoring with coherent institutional roles and transparent governance structures. When supported by clear policy alignment and systematic monitoring frameworks, EPC-based photovoltaic investments can function as effective instruments for accelerating renewable energy deployment and supporting decarbonization strategies in public sector institutions. Full article

Tool-augmented large language model agents are increasingly proposed for network configuration, but routing protocols differ in the control-plane state each commanded router can observe. This difference creates a specific problem for multi-agent orchestration: agents may coordinate more, yet still fail when correct verification depends on peer- or remote-router evidence. We study this interaction through 350 controlled runs on RIP, OSPF, and BGP tasks implemented with FRRouting and Containerlab, comparing a single-agent baseline with multi-agent orchestration patterns across language models. Protocol-centric trace metrics, including spatial coverage, coordination tax, and cross-router verification gap, are combined with intent-property scores and model-balanced bootstrap analysis. The results show that observability explains performance more clearly than orchestration patterns: multi-agent templates trail the baseline on local RIP feedback, show only small and uncertain gains on single-area OSPF troubleshooting, and remain near zero on stricter multi-area OSPF and BGP tasks where peer-side verification gaps are often complete. The main contribution is therefore a protocol-centered account of when agentic orchestration helps, when it adds coordination cost, and why current architectures face a cross-router verification ceiling. Full article

Background: Coronary heart disease (CHD) has a high global disease burden. According to traditional Chinese medicine theory, the main syndrome type of CHD is the syndrome of intermingled phlegm and blood stasis (SI-GPBS). Tanyu Tongzhi Decoction (TYTZD) exerts clear cardioprotective effects on CHD patients with SI-GPBS, while its specific regulatory mechanism remains unclear. Methods: Clinical serum proteomics and network pharmacology were used to screen key targets and pathways for CHD with SI-GPBS. An APOE^−/− mouse model of CHD complicated with SI-GPBS was established and treated with TYTZD. Transcriptomics, proteomics and WGCNA were combined to screen core genes, with Western blotting, immunofluorescence, co-localization analysis and Carstairs staining for target verification and observation of coronary microthrombosis and endothelial injury. Results: A total of 754 differentially expressed proteins were identified in CHD patients with SI-GPBS, significantly enriched in the platelet activation pathway, with ITGA2B as the upregulated core hub protein. Network pharmacology found 94 active ingredients and 144 therapeutic targets of TYTZD for CHD with SI-GPBS, and key components bound well with ITGA2B. In APOE^−/− mice with SI-GPBS, TYTZD improved cardiac function, reduced blood lipids, myocardial enzymes, aortic lipid deposition and myocardial damage, downregulated ITGA2B, F2RL2, FGA and FGB, inhibited integrin αIIbβ3 signaling, restrained endothelial activation and reduced coronary microthrombosis. Conclusions: TYTZD treats CHD with SI-GPBS mainly by inhibiting platelet activation, improving endothelial dysfunction, and reducing coronary microthrombosis. This study provides experimental basis for TYTZD’s clinical application in CHD with SI-GPBS and new ideas for TCM syndrome–disease combination research. Full article

Background: Smart-city road and intersection management increasingly aims to smooth bus operations and reduce stop-and-go driving, but cities often lack auditable indicators linking routine fleet data with comparable energy and environmental KPIs. Methods: This study develops a Monitoring–Reporting–Verification (MRV) workflow for daily bus records from a 2024 Polish metropolitan fleet (diesel, compressed natural gas (CNG), hybrid, and battery-electric buses). Records were quality checked, harmonized to MJ/km, aggregated to bus-month observations, and analyzed using a linear mixed-effects model with propulsion technology, season, and activity level as fixed effects and vehicle-level random intercepts. Environmental impacts were then calculated under well-to-wheel (WTW) boundaries using Environmental Footprint 3.1 (EF 3.1) impact categories, Poland’s 2024 electricity mix, and illustrative electricity-mix scenarios through 2050. Results: Relative to diesel, BEV and HEV were associated with lower adjusted energy intensity (ratios 0.272 and 0.681, respectively), whereas the CNG–diesel contrast was directionally higher but statistically inconclusive under the available CNG sample. BEV energy intensity more than doubled in winter in descriptive terms, and vehicle-specific heterogeneity remained high (ICC ≈ 0.61). The BEV climate profile improved under electricity decarbonization, while some EF categories showed mix-dependent trade-offs. The 3–10% traffic-management variants are interpreted as screening assumptions rather than measured ITS effects. Conclusions: Routine bus records can support auditable MRV and preliminary screening of fleet and corridor interventions, but causal traffic-management evaluation requires route-level trajectory, congestion, and before–after data. Full article

Objective: To develop and validate a fully automated deep learning workflow that localizes key anatomical landmarks on standard canine hindlimb lateral radiographs, derives the tibial plateau angle (TPA), and recommends a saw blade size for tibial plateau leveling osteotomy (TPLO) preoperative planning. Study Design: Retrospective validation study. Animals: Two hundred annotated lateral radiographs obtained from 130 dogs representing 14 breeds, with body weights ranging from 2.4 to 38.0 kg. Methods: A customized four-stage U-Net was trained using three complementary grayscale representations (normalized, contrast-enhanced, and gamma-adjusted images) to detect five TPLO-related landmarks. A deterministic geometric module then calculated TPA and mapped the derived osteotomy geometry to the nearest clinically available saw blade class. Results: The mean absolute error for TPA prediction was 1.34 ± 1.73°, and the median absolute error was 0.75°. Overall, 164/200 cases (82.0%) were within 2° and 188/200 cases (94.0%) were within 4.8° of the surgeon reference. Mean bias was −0.39°, the 95% limits of agreement ranged from −4.62° to 3.85°, and Pearson’s correlation coefficient was 0.87. For saw blade size prediction, mean absolute error was 0.32 ± 0.85 mm, exact agreement was achieved in 175/200 cases (87.5%), and all predictions remained within one adjacent class. Conclusions: The proposed pipeline provided clinically useful automated estimates of TPA and saw blade size from routine lateral radiographs. However, occasional high-impact landmark failures remained, indicating that the system should be positioned as an interpretable decision-support tool that requires surgeon verification rather than as an unsupervised autonomous planning system. Full article

Salt cavern Compressed Air Energy Storage (CAES) is one of the critical technologies for energy storage and an important infrastructure supporting the construction of new power systems and facilitating the achievement of the dual carbon goals. The salt rock resources in China are primarily composed of continental strata salt rocks, characterized by high heterogeneity, well-developed thin-layer interbedding, dissolution resistance among different lithologies, and significant creep variations. These features, to some extent, limit the improvement of wellbore construction accuracy, the reliability of abandoned well sealing, the safety of natural gas storage operations, and enhancements in gas injection–brine displacement efficiency. This study takes the continental bedded salt rock in the Dawenkou Basin as the research object and adopts a method combining theoretical analysis and field engineering verification to improve the systematic construction technology system, covering the whole process of drilling engineering, abandoned well plugging, the design of an injection and brine extraction device, and gas injection and brine drainage. The research results optimize four key technologies, including precise wellbore trajectory control, dual-section milling, and multi-stage redundant plugging of abandoned wells and long-term anti-corrosion completion with laser cladding, and dual-mode adaptive gas injection and brine drainage, and improve the technical system from wellbore construction to salt cavity formation. This study can provide valuable theoretical references and engineering demonstration guidance for underground space development projects in similar salt basins in China. Full article

This paper presents a dual-axis sun sensor employing a cross-slit aperture in conjunction with a four-quadrant trapezoidal photodiode layout. The cross-slit configuration enhances angular sensitivity and resolution, while the trapezoidal photodiode geometry preserves a high signal-to-noise ratio at both near-normal incidence and large Sun angles, maintaining reliable directional discriminability around normal incidence. Compared with conventional quad-triangle photodiode layouts, the proposed trapezoidal geometry avoids the rapid collapse of the illuminated area near the triangular apex at large incidence angles, thereby preserving signal margin near the field-of-view boundary. System-level optical verification demonstrates that, after calibration, the proposed sensor achieves an angular accuracy of $\pm 0.3$${}^{\circ }$ (3$\sigma$). To mitigate performance variations induced by temperature drift, an embedded shielded dummy photodiode is incorporated to provide a dark-current reference for compensation. Unlike compensation approaches that mainly rely on pre-characterization or offline calibration, the embedded shielded dummy photodiode provides an in situ, real-time dark-current reference for compensating for temperature-induced signal drift in the actual operating environment. Experimental results under dark conditions indicate that the embedded dummy photodiode served as a dark-current reference for compensating the temperature-dependent dark-current variation in the active photodiodes, reducing the peak-to-peak dark-signal variation by 96% over a temperature range from 20${}^{\circ }\mathrm{C}$–120${}^{\circ }\mathrm{C}$. Furthermore, a pyramid-type sun-sensor architecture is proposed by integrating the dual-axis fine sun sensor with four wide-field coarse sun sensors. This system-level configuration extends the effective Sun field of view from the conventional 120${}^{\circ }$– 180${}^{\circ }$ range to approximately 280${}^{\circ }$, enabling near-hemispherical Sun-angle observability for enhanced attitude determination robustness. Full article

The modal behaviour of the wooden bridge over the Rhine described by Julius Cæsar in the De Bello Gallico is analysed by a simple analytical model, i.e., a Kirchhoff–Love (KL) plate. The overall structure is indeed modelled as a thin plate, representing the walking surface, resting on elastic supports that approximate the compliance of the underlying structure. Firstly, these elastic constraints are represented by linear springs; in a refined step, beam elements with equivalent stiffness and mass are adopted. The system complexity arises from the consequent non-trivial boundary conditions and is tackled by selecting suitable auxiliary functions to operate with discretised equations of motion, in a Galërkin-like approach. MATLAB helped to develop in-house scripts capable of reconstructing the flexural behaviour as the governing parameters vary, without repeated experimental tests. The analytical results are compared with theoretical predictions and between the two assumed elastic supports, allowing verification of model consistency and explanation of differences in the bridge behaviour. The ease of implementation of these codes also enables the evaluation of the structural potential of historical constructions, the investigation of modular characteristics and connections between subcomponents, and the assessment of the effects of external loads. The study of historical structure dynamics is thus relevant not only for reconstruction, but also for modern mechanical design, with potential applications in civil, mechanical, materials, and naval engineering. Full article

Synthetic Aperture Radar (SAR) image interpretation in dynamic scenarios faces critical challenges, including sluggish multi-agent scheduling responses, sub-optimal task-resource matching, and low full-pipeline collaborative efficiency. To address these issues, this paper proposes an autonomous SAR image interpretation algorithm based on a Mission Control Point (MCP)-driven centralized multi-agent collaborative scheduling framework. To address inefficient task–resource matching, a multi-source orchestration model integrating agent states, task characteristics, and environmental dynamics is developed for optimized initial allocation. To mitigate information fragmentation and improve collaboration efficiency across the pipeline, an MCP-based centralized architecture is proposed to achieve unified scheduling and global optimization of multi-stage agents. Furthermore, to enhance adaptability in dynamic environments, a verification-driven adaptive policy continuous optimization mechanism is introduced, allowing the scheduling policy to continuously adapt. Experiments have been conducted on the SARCAP public dataset, and the proposed method achieved a task–agent matching accuracy of 97.98%, an average scheduling latency of 66.1 ms, and a collaborative interpretation speed of 17.9 fps. Compared with MAPPO and conventional centralized scheduling, scheduling efficiency was improved by 12.3% and 18.7%, respectively. Ablation studies further indicate that both the MCP centralized scheduling mechanism and the multi-source information orchestration module significantly contributed to performance, ensuring high accuracy and robustness. Full article

With the rapid deployment of deep neural networks (DNNs) on edge devices, traditional hardware accelerators face significant challenges in terms of data security, computational redundancy caused by sparsity, and uneven utilization of on-chip resources. This paper proposes SaE-FPGA, a secure and efficient DNN accelerator designed specifically for edge FPGA platforms. The architecture introduces three core innovations: (1) Hash-Bypass Processing Unit (HBPU): Integrating a high-speed SHA-256 hardware engine with a hash-sparse bitmap mechanism, it enables real-time data integrity verification within a single clock cycle while skipping computations for redundant zero-value data. (2) Flexible Mixed-Precision Processing Element (FMP): By reconfiguring idle BRAM and LUT resources into an active lookup table multiplication engine, it overcomes the physical bit-width limitations of DSP blocks and supports INT8/INT6/INT4 mixed-precision multiplication. (3) Multi-mode Reconfigurable Streaming Frame (MRSF): A sparse-aware, elastic load balancing and data routing mechanism designed to mask long memory access latencies and ensure high hardware resource utilization. Experimental results on the Zynq 7045 platform demonstrate that SaE-FPGA reduces redundant computations by 23.2% while maintaining high precision and minimizing precision loss. The system effectively mitigates the risk of physical tampering. When tested on ResNet-50, it achieved a 27.2% improvement in energy efficiency and a 2.97× speedup compared to DSP-based FPGA solutions. Furthermore, by fully exploiting the hybrid BRAM-LUT and DSP configuration, the proposed accelerator achieves a remarkable peak throughput of 782.4 GOPS. Full article

The design of active pneumatic upper limb exoskeletons is complicated by the challenge of reliably determining a kinematically safe workspace. Existing analytical kinematic methods are not sufficient to predict geometric collisions between elements of closed kinematic chains, which poses risks of mechanical damage and threats to user safety during exoskeleton operation. This paper proposes a hybrid algorithm for verifying the workspace of a pneumatic exoskeleton, combining analytical modelling in MATLAB R2020b based on the Product of Exponentials (PoE) method with high-performance static simulation in the Unity environment. At the initial stage, a discrete set comprising 758 million positions of the upper exoskeleton manipulator was generated. Subsequently, a multithreaded two-stage filtering process was implemented: analytical verification of rod stroke limits and angular constraints, followed by the detection of physical intersections of solid-state meshes using the PhysX engine. The results indicate that while the analytical model filters out 99.6% of invalid configurations. Yet, among the remaining positions—formally correct from a mathematical standpoint—up to 50% lead to critical geometric collisions or breaks in the kinematic chain. The computational efficiency of the proposed architecture enabled full static workspace verification in under 20 min. A reachable zone topology was established, revealing pronounced asymmetry and the presence of a “manoeuvrability core” in the user’s anterior hemisphere. The developed algorithm generates a verified set of kinematically safe exoskeleton states, providing a foundation for the kinematic safety layer of a hierarchical control system. These findings demonstrate the necessity of complementing analytical kinematics with physical collision detection when designing hybrid kinematic mechanisms, and the approach can be applied to verify collision-free movement trajectories in various robotic systems. The approach can be applied to verify collision-free movement trajectories in simulation, with physical validation deferred to future work. Full article

The $\delta$-complement $G_{\delta }$ of a graph G, introduced by Pai et al., is a variant of the ordinary complement that toggles edges only between vertices of equal degree. Tangjai et al. recently established Nordhaus–Gaddum-type bounds for the ordinary domination number on G and $G_{\delta }$, raising the natural question of analogous bounds for stronger domination invariants. We prove a sharp Nordhaus–Gaddum-type bound on the Roman domination number of the form ${\gamma }_R\left(G\right)+{\gamma }_R\left(G_{\delta }\right)\le n+3k-2s_1-s_2$, where n is the order of G, k is the number of distinct vertex degrees, and $s_1,s_2$ count degree classes of size 1 and 2, respectively. The bound strictly refines the trivial estimate $2(n+k)$ and is attained on an explicit infinite family of graphs of the form $m{K}_2$. For the total domination number, we pose the corresponding conjecture ${\gamma }_t\left(G\right)+{\gamma }_t\left(G_{\delta }\right)\le n+2k$ whenever G and $G_{\delta }$ have no isolated vertices. We are able to settle this bound only in part: we prove it unconditionally on the subclass of graphs whose every degree-class subgraph and its complement are free of isolated vertices, and we verify it computationally for all orders $3\le n\le 8$, but a proof in full generality remains open, so the bound is stated as a conjecture. The Roman bound is likewise checked by exhaustive enumeration of all $13,595$ non-isomorphic simple graphs of orders $3\le n\le 8$, with zero violations and all 26 sharp instances identified. Full article

The wet-rail phenomenon can cause low adhesion, which negatively affects railway operation. It is believed to occur when small amounts of water mix with solid particles on wheel and rail surfaces, e.g., wear debris or iron oxides, forming a dense suspension in the wheel–rail contact, leading to sharp adhesion drops. Mini Traction Machine (MTM) tests using water-based suspensions with different particles also show adhesion drops during water evaporation, which can be linked to the wet-rail phenomenon. While the physical mechanisms underlying the adhesion drop are unclear, it is hypothesised that rapid loading raises fluid pressure in the suspension, separating wheel and rail surfaces, reducing force transfer through particle contact, thereby reducing the suspension’s shear strength. For verification, a coupled Discrete Element Method and fluid dynamics model is used to simulate a simplified MTM setting and steps towards full scale wheel–rail contact. During simulation of rapid loading, fluid pressure rises but remains negligible compared to applied contact stresses in all considered cases. Thus, it is unlikely that hydrodynamic pressure build-up within the suspension contributes significantly to the low adhesion observed. Future research should investigate additional mechanisms, such as reduced shear strength of deformed or crushed wet particles under high normal loading conditions. Full article

The thermodynamic prediction of the fast refueling process for vehicular hydrogen storage cylinders faces the complex problem of modeling multi-layer composite walls. Drawing on the series thermal resistance principle, this paper introduces an equivalent thermal conductivity approach, simplifying the multi-layer structure into homogeneous material. Combined with the real-gas-state equation, a coupled thermodynamic framework combining zero-dimensional gas dynamics and one-dimensional cylinder wall heat transfer is developed. The comparison and verification with the 70 MPa fast charging experimental data have demonstrated that the proposed model exhibits sufficient accuracy and robustness for the problem. By comparing the temperature rise changes of different volume type-III gas cylinders, it was found that the surface area-to-volume ratio (A/V) was the primary geometric factor—the key geometric parameter that governs the temperature rise behavior. Larger volume gas cylinders exhibit more significant temperature rise due to their lower heat dissipation efficiency. A further comparison of the thermal response characteristics between Type-III and Type-IV cylinders demonstrates that the equivalent thermal conductivity is the dominant parameter determining the temperature rise behavior: The lower this coefficient, the stronger the limitation on the cylinder’s heat dissipation capacity, and the more pronounced the temperature rise. The proposed method not only ensures accuracy but also reduces the complexity of the modeling process, providing an efficient theoretical tool for optimizing the refueling strategy and conducting thermal safety assessment of vehicular hydrogen storage systems. Full article

Airfield Ground Lighting Power Systems (AGLPS) are critical for ensuring safe aircraft operations, particularly under low-visibility conditions. Conventional systems are based on series circuits supplied by constant current regulators, which impose limitations in terms of flexibility, scalability, and maintenance. This work investigates an alternative AGLPS architecture based on a low-voltage parallel distribution network enabled by LED luminaires, distributed power electronics, and Power Line Communication (PLC) for control and monitoring. A theoretical and conceptual approach is adopted, including electrical modelling of the power distribution system, verification of conductor sizing under high admissible voltage drops, and evaluation of communication performance using PLC and Modbus protocols. The results demonstrate that the proposed architecture can operate with significantly higher voltage drops without affecting luminous output, allowing for the use of standard low-voltage cabling. In addition, communication analysis shows that control and monitoring operations can be executed within a few milliseconds, meeting operational requirements. An economic assessment indicates a reduction in system complexity and overall costs compared to conventional series systems. The findings confirm that parallel AGLPS architectures constitute a technically feasible and advantageous alternative to traditional systems, enabling enhanced flexibility, improved maintainability, and the integration of advanced digital functionalities. Full article