Search Results (88)

The economic dispatch (ED) problem is a major challenge in power system optimization. In this article, an Enhanced Social Group Optimization (ESGO) algorithm is presented for solving the economic dispatch problem with or without wind units, considering various characteristics related to valve-point effects, ramp-rate constraints, prohibited operating zones, and transmission power losses. The Social Group Optimization (SGO) algorithm models the social dynamics of individuals within a group—through mechanisms of collective learning, behavioral adaptation, and information exchange—and leverages these interactions to guide the population efficiently towards optimal solutions. ESGO extends SGO along three complementary directions: redefining the update relations of the original SGO, introducing stochastic operators into the heuristic mechanisms, and dynamically updating the generated solutions. These modifications aim to achieve a more robust balance between exploration and exploitation, enable flexible adaptation of search steps, and rapidly integrate improved-fitness solutions into the evolutionary process. ESGO is evaluated in six distinct cases, covering systems with 6, 40, 110, and 220 units, to demonstrate its ability to produce competitive solutions as well as its performance in terms of stability, convergence, and computational efficiency. The numerical results show that, in the vast majority of the analyzed cases, ESGO outperforms SGO and other known or improved metaheuristic algorithms in terms of cost and stability. It incorporates wind generation results at an operating cost reduction of approximately 10% compared to the thermal-only system, under the adopted linear wind power model. Moreover, relative to the size of the analyzed systems, ESGO exhibits a reduced average execution time and requires a small number of function evaluations to obtain competitive solutions. Full article

In this study, the economic dispatch problems, which are indispensable in electrical engineering, are addressed utilizing Grey Wolf Optimization (GWO). Conventional mathematical methods struggle to provide quick, reliable solutions to nonlinear problems in power systems with many generation units. An economic dispatch solution operates by allocating generation sets with the lowest fuel costs to meet predetermined power balance constraints. GWO is a meta-heuristic set of rules that has garnered significant attention in the literature due to its suitable exploratory and exploitative properties, rapid and mature convergence rate, and straightforward architecture. When dealing with a nonlinear constraints problem, such as ED, it has gained significant recognition for its balance of exploration and exploitation, reliable convergence characteristics, and simple implementation framework. The proposed Grey Wolf Optimization algorithm is evaluated using real-world generation case benchmark comparisons for 3-unit, 6-unit, and 15-unit systems. Results demonstrate the impact of incorporating renewable energy source (RES) uncertainty; fuel costs increase significantly from USD 7598 to USD 21,240 for the 3-unit system, USD 13,397 to USD 46,216,658 for the 6-unit system, and USD 32,622.55 to USD 33,723.11 for the 15-unit system, highlighting that RES integration is more economically viable in larger systems. The paper’s significant contribution is its essential mechanism for power systems, which enables lower global energy costs, improved operational efficiency, and enhanced grid reliability through strategic resource allocation in a constrained economic dispatch energy management system. Full article

Autonomous vehicles (AVs) at SAE Levels 3 require a take-over request to switch from autonomous to manual mode when leaving the operational design domain (ODD). An appropriate take-over request lead time (TORlt) is necessary for safe interaction between AVs and non-AVs. This study developed a methodology to derive the optimal TORlt for AVs entering the area out of the ODD using a multi-agent driving simulator experiment. The multi-criteria decision-making method was adopted to integrate evaluation indicators to derive an optimal TORlt. The TORlt was defined as 3, 6, 9, 12, and 15 s in the driving simulation experiment scenario. The driving simulation experiment was conducted with a total of 60 participants. The simulation network was a two-lane urban road in each direction with a total length of 1.7 km, including a school zone where the autonomous driving mode is prohibited. Three requirements were established to determine the optimal TORlt: minimizing the take-over time, maximizing the success rate of take-over, and minimizing the potential of rear-end collisions due to vehicle interactions. After conducting comparative analyses of individual evaluation indicators for each scenario, a multi-criteria decision-making method was used for integrated evaluation to determine the optimal TORlt. It was found that the optimal TORlt for AVs on urban roads is 9 s. The results of this study can be used as valuable fundamentals in determining take-over requests for AVs toward safer vehicle interactions in the traffic stream. Full article

Wire Arc Additive Manufacturing (WAAM) enables cost-effective fabrication of complex metallic components but faces challenges in achieving consistent tensile strength for cylindrical parts with intricate internal features (e.g., cooling channels, helical grooves), where conventional machining is often infeasible or prohibitively expensive. This study introduces a novel stacked ring substrate strategy with pre-formed low-carbon steel rings defining complex internal geometries, followed by external WAAM deposition using ER70S-6 wire to overcome these limitations. Five process parameters (welding current: 110–130 A; offset distance: 2.5–3.0 mm; Step Length: rotary to straight; torch speed: 400–500 mm/min; weld thickness: 2.0–3.0 mm) were optimized using a Taguchi L25 orthogonal array (25 runs in triplicate). ANOVA identified Step Length as the dominant factor, with straight paths significantly reducing thermal cycling and improving interlayer bonding, alongside a notable current × speed interaction. Optimal settings achieved tensile strengths of 280–290 MPa, significantly below wrought ER70S-6 benchmarks (400–550 MPa) due to interfacial weaknesses at ring fusion zones and thermal accumulation from stacked cylindrical geometry, a limitation acknowledged in the absence of microstructural or thermal history data. A Random Forest Regressor predicted strength with R² = 0.9312, outperforming conventional models. This hybrid approach significantly enhances design freedom and mechanical reliability for high-value cylindrical components in aerospace and tooling, establishing a scalable, data-driven framework for geometry-constrained WAAM optimization. Full article

Skin pathogenic microbes continue to seriously endanger humans, particularly resistant strains. Nanomaterials/composites are promising answers for this. Black mulberry (MB) polysaccharides were employed for biosynthesizing/capping selenium nanoparticles (SeNPs); their conjugations alongside chitosan (Cht) nanoforms were constructed and assessed for skin pathogens’ (Staphylococcus aureus bacteria and Candida albicans yeast) suppression and destruction. The biosynthesis of SeNPs with MB was verified using FTIR analysis and UV-vis spectroscopy. The nanocomposites were constructed from Cht–MB-SeNPs at concentrations of 2:1 (F1), 1:1 (F2), and 1:2 (F3). The SeNPs had a mean diameter of 46.19 nm, whereas the F-2 nanocomposites had the lowest particle diameter (212.42 nm) compared to F-1 (239.88 nm) and F-3 (266.16 nm) nanocomposites. The F-2 nanocomposites significantly exhibited the strongest antimicrobial efficacy against skin pathogens, with 26.3 and 27.1 mm inhibition zones and 22.5 and 20.0 μg/mL inhibitory concentrations against bacteria and C. albicans yeast, respectively. The scanning imaging of microbes exposed to nanocomposite emphasized the severe destruction/lyses of microbial cells within 10 h. Loading of cotton fabrics with nanomaterials, particularly with Cht/MB-SeNP nanocomposites, generated potent durable antimicrobial textiles that could prohibit microbial growth, with inhibition zones of 6.2 mm against C. albicans and 3.7 mm against S. aureus; the textiles could preserve their antimicrobial actions after two washing cycles. The biogenic construction of Cht/MB-SeNP nanocomposites can provide innovative solutions to manage and control skin pathogens. Full article

Traffic assignment in large urban areas is an old but increasingly important problem because of the rapid growth of the world population and traffic demands. Many algorithms have been developed but their convergence rates and complexities are still prohibitive for real-time applications. The recently developed MinSum algorithm introduces a new approach. It is a highly efficient discrete-domain optimization algorithm for system-optimized route assignment between two city zones. Its complexity (the number of critical operations) is O(R³), where R is the number of routes. Nonetheless, there is still room for improvements, and this paper presents two modified MinSum variants, heuristic and approximate, that are significantly faster and of lower complexity, while retaining MinSum’s prominent features. Heuristic variant MinSumH is up to five times faster than MinSum and its complexity theoretically remains O(R³), though experiments indicate that it is closer to O(R²). Approximate variant MinSumA is faster by up to over 100 times and reduces the complexity to O(R). Both proposed variants are progressively faster as R grows. Due to their high convergence rate and exceptionally low complexity, along with other prominent features, the proposed algorithms are ready for real-time system-optimal traffic assignment in a real urban environment. Full article

This article presents the results of a rockfall analysis conducted for the limestone walls of a former quarry that is now used as an urban park. The performed simulations (2D statistical analysis using Rigid Body Impact Mechanics—RBIM and Discrete Element Modelling—DEM) enabled the determination of the maximum displacement range during the ballistic phase and the maximum rebound height at the slope base, which facilitated the delineation of a safe land-use zone. A hazard zone was also identified, within which public access must be strictly prohibited due to the risk posed by flying debris. Based on slope stability assessments (safety factor values and rockfall trajectories), recommendations were formulated for slope reinforcement measures and appropriate management actions for designated sections to ensure safe operation of the site. Three mitigation strategies were proposed: (1) no protective measures, (2) no structural reinforcements but with installation of a rockfall barrier, and (3) full-scale stabilisation to allow unrestricted access to the quarry walls. The first option—leaving slopes unsecured with only designated safety buffers—is not recommended. Full article

The Economic Dispatch Problem (EDP) plays a critical role in power system operations by trying to allocate power generation across multiple units at minimal cost while satisfying complex operational constraints. Traditional optimization techniques struggle with the non-convexities introduced by factors such as valve-point effects, prohibited operating zones, and spinning reserve requirements. While metaheuristics methods have shown promise, they often suffer from convergence issues and constraint-handling limitations. In this study, we introduce a novel application of Group Relative Policy Optimization (GRPO), a reinforcement learning framework that extends Proximal Policy Optimization by integrating group-based learning and relative performance assessments. The proposed GRPO approach incorporates smart initialization, adaptive exploration, and elite-guided updates tailored to the EDP’s structure. Our method consistently produces high-quality, feasible solutions with faster convergence compared to state-of-the-art metaheuristics and learning-based methods. For instance, in the case of the 15-unit system, GRPO achieved the best cost of USD 32,421.67/h with full constraint satisfaction in just 4.24 s, surpassing many previous solutions. The algorithm also demonstrates excellent scalability, generalizability, and stability across larger-scale systems without requiring parameter retuning. These results highlight GRPO’s potential as a robust and efficient tool for real-time energy scheduling in smart grid environments. Full article

Within urban tunnels, the lane boundary lines are typically solid, thereby prohibiting lane changes and overtaking. The establishment of a mobile operation zone in the slow lane can pose significant driving safety hazards not only to the slow lane within the tunnel but also to the middle and overtaking lanes at the tunnel exit. This article adopts the method of simulation of the establishment of an urban expressway three-lane VISSIM model, and selects the road traffic volume and speed of moving work zone as the independent variable parameters. Then, the influence range of a low-speed vehicle on the rear vehicles in the middle lane and slow lane and the traffic risk caused by a low-speed vehicle are analyzed. The results show that, irrespective of the variations in traffic volume and moving operation zone speed, the traffic flow within a 150 m range after the tunnel section was significantly influenced. This was because queuing and congested vehicles from the slow lane exited the tunnel, causing vehicles to change lanes and overtake in a concentrated manner. The moving operation zone has a substantial impact on the traffic flow in the slow lane. Under different moving operation zone speed conditions, the speed change trend of the following vehicles is consistent. When the moving operation zone speed was 5 km/h and the traffic volume exceeded 1200 pcu/h, the traffic flow behind the operation zone was directly affected, and within an observable longitudinal distance of 500 m, this impact did not dissipate. The research results can provide a scientific basis for the operation and management of urban tunnel low-speed vehicles. Full article

Against the backdrop of ecological civilization construction and regional coordinated development strategies, functional zone (MFOZ) planning guides national spatial development through differentiated policies. However, a prominent conflict exists between the ecological protection responsibilities and regional development rights in restricted and prohibited development zones, leading to a vicious cycle of “ecological protection → restricted development → poverty exacerbation”. This paper focuses on the synergistic mechanisms between ecological compensation and targeted poverty alleviation. Based on the capability approach and sustainable development goals (SDGs), it analyzes the dialectical relationship between the two in terms of goal coupling, institutional design, and practical pathways. The study finds that ecological compensation can break the “ecological poverty trap” through the internalization of externalities and the enhancement of livelihood capabilities. Nevertheless, challenges remain, including low compensation standards, unbalanced benefit distribution, and insufficient legalization. Through case studies of the compensation reform in the water source area of Southern Shaanxi, China, and the Common Agricultural Policy (CAP) of the European Union, this paper proposes the construction of a long-term mechanism integrating differentiated compensation standards, market-based fund integration, legal guarantees, and capability enhancement. The research emphasizes the need for institutional innovation to balance ecological protection and livelihood improvement, promoting a transition from “blood transfusion” compensation to “hematopoietic” development, thereby offering a Chinese solution for global sustainable development. Full article

Infrastructure facility development and modernization highly contribute to national economic growth, but at the same time, such development also causes local negative impacts on the use of specific land plots, creating losses for their right holders. In Russia, some prerequisites have already been laid down on the issue of compensation for the losses associated with restrictions on the rights and prohibitions of economic activity within zones with special territory use conditions (ZSTUCs). However, the impacts of such facilities lead to environmental pollution and land use disadvantages, such as irregular parcels. The aim of this work is to substantiate a set of approaches to compensating for the cumulative negative impact of infrastructure facilities. The factors causing the negative impacts of infrastructure facilities are grouped into three areas: rights restrictions, territorial deficiencies and environmental pollution. This work uses the SWOT analysis method with the possibility of element-by-element analysis, as a result of which the approaches to the compensation for negative impacts under different external and internal conditions are determined. As a result of this study, a justification for a set of approaches to compensating for the negative impacts of infrastructure facilities on land use was executed, and a new algorithm to compensate the right holders of the land, industry sector or state for such negative impacts was developed. The following approaches to compensating for negative impacts were identified: loss assessment; the establishment of environmental payments; cadastral value adjustment; compensation for industry sector losses; and the use of state regulation tools. The first two approaches were identified as the main ones. The proposed algorithm can be realized only with the help of the abovementioned methodological approaches, which form a basis for further research. Full article

This study examines the morphology and development of Dobreștilor–Brusturet Cave, located in the Brusturet gorge at the western edge of the Bran–Dragoslavele Corridor, an important tourist route in the Romanian Carpathians. The research aims to analyze the geomorphological characteristics and establish the heritage value of the Dobreştilor Cave geomorphosite, supporting protection efforts for invertebrate species that led to the cave’s designation as a natural monument. The inventory of physical features prompted the Piatra Craiului National Park Scientific Council to consider including this speleological site in a thematic geotourism circuit called “The Road of Gorges and Caves in the Upper Basin of the Dâmbovițean”, integrated within protected areas. This represents the first geomorphological study of the cave. Given its ecological significance within the national park’s strict protection zone, recreational tourism is prohibited. The cave should only be used as a geotourism resource for scientific research and education. Morphogenetic analysis reveals that the cave has evolved in a vadose hydrological regime since the Pleistocene, with cavity expansion influenced by free-flowing water alternating with that under pressure during torrential episodes, concomitant with the precipitation of calcium carbonate that formed various speleothems. This research supports documentation for promotional materials and could assist local authorities in the Dâmbovicioara commune with geotourism development decisions, potentially integrating the site into a proposed “Moieciu–Fundata–Dâmbovicioara–Rucăr Geological and Geomorphological Complex”. Full article

The current study reveals a deficiency in knowledge regarding the assessment of the breadth of prohibitions and restrictions on water withdrawal for the development and utilization of geothermal resource projects involving water withdrawal. To resolve this matter, this report outlines the extent of water withdrawal prohibitions and restrictions for geothermal energy development and use projects, with a particular focus on Lindian County’s medium- and low-temperature geothermal resources of the sedimentary basin type. A comprehensive consideration of geological, hydrological, and other factors was made in light of the need for global energy transformation and the benefits and drawbacks of geothermal energy. The study first divided Lindian County into 17 zones using the zoning method of dominant sign and superposition method, which was then combined with the hierarchical analysis method. The evaluation indexes were then quantitatively graded and evaluated in the 17 zones using the linear weighted sum method, and each zone’s suitability for water abstraction was ultimately determined. The limited and banned water withdrawal range of the Lindian County geothermal energy development and utilization project is defined based on the water withdrawal characteristics of the 17 subareas. The rational development of geothermal energy, the preservation of the natural environment, and the advancement of the geothermal industry in Lindian County are all greatly impacted by this study, which offers a more sophisticated methodology for the assessment of water withdrawal type projects of sedimentary basin-type medium- and low-temperature geothermal resources. Full article

The use of remote sensing images to analyze the change characteristics of large-scale aquaculture areas and monitor aquaculture violations is of great significance for exploring the law of marine aquaculture and assisting the monitoring and standardization of aquaculture areas. In this study, a violation monitoring framework for marine aquaculture areas based on image recognition using an enhanced Mask R-CNN architecture incorporating a convolutional block attention module (CBAM) and soft non-maximum suppression (Soft-NMS) is proposed and applied in Sandu’ao. The results show that the modified Mask R-CNN, when compared to the most basic Mask R-CNN model, exhibits higher accuracy in identifying marine aquaculture areas. The aquaculture patterns in the Xiapu region are characterized by two peak periods of aquaculture area fluctuations, occurring in March and October. Conversely, July marks the month with the smallest aquaculture area in the region and is influenced by factors such as water temperature and aquaculture cycle. Significant changes in the aquaculture area were observed in January, March, June, August, and October, necessitating rigorous monitoring. Furthermore, monitoring and analysis of aquaculture areas have revealed that despite the reduction in illegal aquaculture acreage since 2017 due to the implementation of functional zone planning for marine aquaculture areas, illegal aquaculture activities remain prevalent in prohibited and restricted zones in Xiapu, accounting for a considerable proportion. Full article

The paper presents an application of a new, simple approach for the naturalistic assessment of road sign quality from a driver’s perspective, using dashboard camera recordings. This method was used to evaluate signage along a 69.6 km road construction zone in Poland associated with the phased upgrade of a dual carriageway with unlimited access into a motorway. The analysis focused on three distinct phases of the roadwork: the beginning of roadwork, the progress of roadwork, and finishing roadwork. The correctness, visibility, and quality of the road signs were assessed on a specially developed scale. The study found that 1135 road signs were unnecessary, which was equal to 36% of all signs. The majority of all signs (48.1%) indicated prohibition: more than one third (33.6%) of them were speed limit signs, of which 52% were posted without the need. It was demonstrated that the simple method applied in this study can be considered a useful tool to identify deficiencies in signage, which could ultimately improve road safety and make road management more sustainable. Moreover, this study confirmed again that the use of appropriate video recordings makes it faster and easier to conduct an inventory of road signs. Full article