Efficient and accurate insulator defect detection is essential for maintaining the safe and stable operation of transmission ***,the detection effectiveness is adversely impacted by complex and changeable environmenta...
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Efficient and accurate insulator defect detection is essential for maintaining the safe and stable operation of transmission ***,the detection effectiveness is adversely impacted by complex and changeable environmental backgrounds,particularly under extreme weather that elevates accident ***,this research proposes a high-precision intelligent strategy based on the synthetic weathera* algorithm and improved YOLOv7 for detecting insulator defects under extreme *** proposed meth-odology involves augmenting the dataset with synthetic rain,snow,and foga* algorithm ***,the original dataset undergoes augmentation through affine and colour transformations to improve model's generalisation performance under complex power inspection *** achieve higher recognition accuracy in severe weather,an improved YOLOv7a* algorithm for insulator defect detection is proposed,integrating focal loss with SIoU loss function and incorporating an optimised decoupled head *** results indicate that the synthetic weathera* algorithm processing significantly improves the insulator defect detection accuracy under extreme weather,increasing the mean average precision by 2.4%.Furthermore,the authors’improved YOLOv7 model achieves 91.8%for the mean average precision,outperforming the benchmark model by 2.3%.With a detection speed of 46.5 frames per second,the model meets the requirement of real-time detection of insulators and their defects during power inspection.
The gravitational lensing wave effect generated by a microlensing field embedded in a lens galaxy is an inevitable phenomenon in strong lensed gravitational waves(SLGWs).This effect presents both challenges and opport...
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The gravitational lensing wave effect generated by a microlensing field embedded in a lens galaxy is an inevitable phenomenon in strong lensed gravitational waves(SLGWs).This effect presents both challenges and opportunities for the detection and appli-cation of ***,investigating this wave effect requires computing a complete diffraction integral over each microlens in the *** is extremely time-consuming due to the large number of microlenses(10^(3)-10^(6)).Therefore,simply adding all the microlenses is ***,the complexity of the time delay surface makes the lens plane resolution a crucial factor in controlling numerical *** this paper,we propose a trapezoid approximation-based adaptive hierarchical tree algo-rithm to meet the challenges of calculation speed and *** find that thisa* algorithm accelerates the calculation by four orders of magnitude compared to the simple adding method and is one order of magnitude faster than the fixed hierarchical treea* algorithm proposed for electromagnetic *** importantly,oura* algorithm ensures controllable numerical errors,increasing confidence in the *** with our previous work(***.66,239511,2023),this paper addresses all numerical issues,including integral convergence,precision,and computational time1).Finally,we conducted a population study on the microlensing wave effect of SLGWs using thisa* algorithm and found that the microlensing wave effect cannot be ignored,especially for Type II SLGWs(from saddle position of the time delay surface)due to their intrinsic geometric structures and their typical intersection with a denser microlensing ***,more than 33%(11%)of SLGWs have a mismatch larger than 1%(3%)compared to the unlensed ***,we found that the mismatch between signal pairs in a doubly imaged GW is generally larger than 10^(−3),and 61%(25%)of signal pairs have a mismatch larger than 1%(3%).Theref
This paper presents a new approach to optimizing route selection in urban road networks with sparsely placed traffic counters. By leveraging graph theory and Dijkstra'sa* algorithm, we propose a new method to determ...
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This paper presents a new approach to optimizing route selection in urban road networks with sparsely placed traffic counters. By leveraging graph theory and Dijkstra'sa* algorithm, we propose a new method to determine the shortest path between origins and destinations in city traffic networks with sparsely placed counters. The method is based on the similarities between traffic flows recorded at the counter and the streets that generate traffic for a given counter. The advantage of this method is the use of a secondary counter function to obtain data that are built into the shortest path determination model and the free choice of the time of day for which the path is searched. The proposed method is implemented using the programming language AutoLISP 2022 and program AutoCAD 2022, providing a valuable tool for transportation engineers and urban planners. This paper presents a model of the shortest path that integrates one-way streets, the average speed of the car, as well as the delay time at traffic-lighted and non-traffic intersections. The model was applied to the traffic network of the city of Sarajevo (Bosnia and Herzegovina), but there are no restrictions for application to any network equipped with traffic counters. The obtained results show a high agreement with the Google Maps service as a reference system.
Residential load scheduling in smart power grids (SPGs), especially those incorporating renewable energy sources (RESs), storage battery, and demand response (DR) faces significant challenges due to the limitations of...
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Residential load scheduling in smart power grids (SPGs), especially those incorporating renewable energy sources (RESs), storage battery, and demand response (DR) faces significant challenges due to the limitations of traditional optimizationa* algorithms. These challenges include premature convergence, high computational costs, imbalanced exploration and exploitation, lack of adaptability, and sensitivity to parameters. Such issues make it difficult to effectively manage energy consumption, alleviate peak loads, and reduce energy costs while maintaining user comfort. To address these challenges, we propose an improved particle swarm optimization (IPSO)a* algorithm that enhances exploration and exploitation balance through inertia weight adjustment, velocity damping, and the inclusion of crossover and mutation strategies. These enhancements prevent premature convergence and allow for faster, more accurate convergence to optimal solutions. The proposed IPSO is integrated into a power usage scheduler (PUS) for optimal residential load scheduling under an adaptive pricing scheme considering photovoltaic (PV) and storage battery, focusing on reducing peak energy usage, rebound peaks, energy costs, and user discomfort. The effectiveness of the IPSO-based PUS is demonstrated through a comparison with other optimizationa* algorithms such as genetic optimizationa* algorithm (GOA), particle swarm optimization (PSO), and wind-driven optimization (WDO). Results show that the IPSOa* algorithm consistently outperforms these alternatives in terms of energy consumption, peak energy alleviation, cost reduction, and grid stability, while also achieving faster execution times and superior convergence rates. This work provides a robust solution for residential load scheduling, offering significant insights and practical benefits for energy optimization in SPGs.
Aiming at solving the production scheduling problems in flexible manufacturing systems including the flexible job shop scheduling (FJSP) and distributed flexible job shop scheduling (DFJSP) with operation outsourcing,...
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Aiming at solving the production scheduling problems in flexible manufacturing systems including the flexible job shop scheduling (FJSP) and distributed flexible job shop scheduling (DFJSP) with operation outsourcing, which are two kinds of typical NP-hard problems, the general mathematical model with two optimization objectives including minimizing the total costs as well as makespan are developed. Then, an innovative discrete water source cyclea* algorithm (IDWCA) inspired by the water cycle process is proposed to address the model. In the IDWCA, the operators including evaporation mixing, precipitation, local mixing, modification of water source composition and water source loss are designed to search for optimization solutions. Finally, 15 FJSP comparison experiments and 45 DFJSP comparison experiments with different scales are provided to verify the comprehensive performance of the IDWCA, in which the IDWCA, the original water cyclea* algorithm (OWCA), and the two general meta-heuristica* algorithms genetica* algorithm (GA) and particle swarm optimization (PSO) are involved. Compared with OWCA, GA and PSO, IDWCA performs significantly better in all FJSP experiments, while it performs better in 43 out of 45 DFJSP experiments, and its advantages are more significant in solving the medium-scale and large-scale problems. In addition, the evolutionary curves of the abovea* algorithms indicate that the IDWCA has the better convergence speed and results than that of OWCA, GA and PSO. Therefore, the developed mathematical model and IDWCA are effective in solving the studied FJSP and DFJSP, the proposeda* algorithm enriches the theoretical researches on meta-heuristica* algorithms and production scheduling.
To address the deficiency and predict the adsorption performance in different adsorbents, this study proposes a new optimizer linked to the machine learning (ML) model considering the performance of the adsorption pro...
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To address the deficiency and predict the adsorption performance in different adsorbents, this study proposes a new optimizer linked to the machine learning (ML) model considering the performance of the adsorption process. The main goal is to predict adsorption under different process conditions with different adsorbents and provide a unified framework, leading to the prediction of adsorption phenomena instead of traditional isotherm models. This research focuses on predicting the adsorbed amount of O2 and N2 on several carbon-based adsorbents using the ML approach linked to the grey wolf optimizera* algorithm (GWO). Experimental isotherm data (dataset 1344) on adsorbent type, temperature, pressure, gas type, and adsorption capacity of the process adsorption were used as input and output datasets. The besta* algorithm was Broyden-Fletcher-Goldfarb-Shanno (BFGS), a two-layer network from a multi-layer perceptron (MLP) method applying 28 neurons. The new MLP-GWO network would have the best mean square error (MSE) efficiencies of 0.00037, while the R2 (r-squared) was 0.9934. The new ML-generated model can accurately predict the adsorption process behaviour of different carbon-based adsorbents under various process conditions. The results of this research have the potential to assist a wide range of gas separation industries.
Transportation infrastructure has often been the target of terrorist attacks, and mitigation of the risk of toxic gas attacks is a challenging task in the design of indoor emergency evacuation systems. Considering mul...
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Transportation infrastructure has often been the target of terrorist attacks, and mitigation of the risk of toxic gas attacks is a challenging task in the design of indoor emergency evacuation systems. Considering multiple emergency response modes, we propose an agent-based risk assessment model and itsa* algorithm to integrate gas diffusion and pedestrian movement data for emergency response, quickly assessing average individual exposure risk. We assessed the exposure status of individuals with respect to their emergency response actions following a toxic gas attack in an airport terminal. The results indicate that in the event of a general gas attack on an airport terminal, ventilation must be immediately ceased along with early evacuation. In areas with a shelter-in-place environment, the ventilation mode and shelter-in-place time should be determined based on the concentration of indoor and outdoor gases. In areas with nerve gas exposure and high population density, a new exit must be established at evacuation bottlenecks, and pedestrians must be guided to evacuate while promptly closing ventilation. These results offer suggestions and strategies for emergency response and decision-making in airport terminals during such incidents.
作者:
Yu, Jia aoSun, YiqingShen, ZhenzhongGan, LeiHohai Univ
Coll Water Conservancy & Hydropower Engn Nanjing 210024 Peoples R China Minist Transport
Key Lab Transport Ind Comprehens Transportat Theor Nanjing Modern Multimodal Transportat Lab Nanjing 211100 Peoples R China Hohai Univ
State Key Lab Hydrol Water Resources & Hydraul Eng Nanjing 210024 Peoples R China Southeast Univ
Sch Transportat Nanjing 211189 Peoples R China
The monitoring data analysis and numerical calculation for the deformation of earth rock dams are essential basis for structural state assessment. However, due to the complexity of high rockfill dam, conventional fini...
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The monitoring data analysis and numerical calculation for the deformation of earth rock dams are essential basis for structural state assessment. However, due to the complexity of high rockfill dam, conventional finite element (FE) calculation and inverse analysis methods are often difficult to accurately reconstruct the deformation field of the dam body. In this paper, the improved multi-objective cuckoo search (IMOCS)a* algorithm was combined with the response surface model (RSM) to perform multi-objective joint inverse analysis for instantaneous and creep deformation parameters of a high rockfill dam, which is verified to have superiorities in aspects of iteration efficiency, coverage and uniformity of solution sets. Eventually, the reasonable mechanical parameters of rockfill material were obtained, and the settlement process of dam monitoring points was simulated. Unlike the conventional single objective method, the proposed novel method can avoid three issues including the difficulty of separating instantaneous deformation and creep, the inconsistency of buried and start measuring time for deformation monitors, and the neglection for the effect of water level changes during operation. In conclusion, the proposed approach possesses the potential of precise identification for mechanical parameter and the advantage in facilitating the assessment of structural safety for earth rock dams.
Feature detection is one of the hot topics in the weather radar research community. This study employed a convective-stratiform classificationa* algorithm to detect features in polarimetric radar variables and Quantitat...
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Feature detection is one of the hot topics in the weather radar research community. This study employed a convective-stratiform classificationa* algorithm to detect features in polarimetric radar variables and Quantitative Precipitation Estimation (QPE) retrieval during a heavy precipitation event in Crossville, Tennessee, during warm-season convection. Analysis of polarimetric radar variables revealed that strong updrafts, mixed-phase precipitation, and large hailstones in the radar resolution volume during the event were driven by the existence of supercell thunderstorms. The results of feature detection highlight that the regions with convective-stratiform cores and strong-faint features in the reflectivity field are similar to those in the rainfall field, demonstrating how thea* algorithm more effectively detects features in both fields. The results of the estimates, accounting for uncertainty during feature detection, indicate that an offset of +2 dB overestimated convective features in the northeast in both the reflectivity and rainfall fields, while an offset of -2 dB underestimated convective features in the northwest part of both fields. The results highlight that convective cores cover a small area with high rainfall exceeding 50 mmh-1, while stratiform cores cover a larger area with greater horizontal homogeneity and lower rainfall intensity. These findings are significant for nowcasting weather, numerical models, hydrological applications, and enhancing climatological computations.
Static analysis of the lateral deformation of a bottomhole assembly (BHA) is essential for controlling borehole trajectories in directional drilling. A major technical challenge in static BHA modeling is efficiently d...
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Static analysis of the lateral deformation of a bottomhole assembly (BHA) is essential for controlling borehole trajectories in directional drilling. A major technical challenge in static BHA modeling is efficiently determining the contact configuration between the BHA and the borehole wall. This configuration, including contact locations and orientations, is not known a priori and introduces nonlinearities into the analysis. Mosta* algorithms addressing the contact problem in BHA modeling are proprietary and lack detailed descriptions. Explicita* algorithms based on the Newton-Raphson iteration method and linear/nonlinear complementarity problem formulations have limitations, such as computational inefficiency and the need for predefined contact locations. In this paper, we derive governing differential equations for 3D BHA static deformation, incorporating nonlinear effects from borehole curvature, axial forces, and both discrete and continuous contacts. The finite element method (FEM) is used to solve these equations under appropriate boundary conditions. Within the finite element framework, the Lagrange multiplier method (LMM) is used to impose displacement constraints at contact points, while an innovative iterative process ensures the unilateral nature of the contacts. Thea* algorithm typically converges in O (10) each iteration involving the solution of approximately O (10(2)) iterations, with finite element equations, ensuring high computational efficiency. Thea* algorithm, grounded in principles of structural mechanics, is robust across a wide range of conditions, and its accuracy is validated against a publisheda* algorithm. The proposed BHA model is further validated using downhole measurements. In one scenario, bending moment on bit (BOB) measurements from a BHA equipped with a rotary steerable system (RSS) shows strong agreement with the model results, both in magnitude and variation pattern, when a fixed displacement boundary condition is applied at the bit. In
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