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Optimal Planning of Multiple PV-DG in Radial Distribution Systems Using Loss Sensitivity Analysis and Genetic Algorithm
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作者 A. Elkholy 《Journal of Power and Energy Engineering》 2025年第2期1-22,共22页
This paper introduces an optimized planning approach for integrating photovoltaic as distributed generation (PV-DG) into the radial distribution power systems, utilizing exhaustive load flow (ELF), loss sensitivity fa... This paper introduces an optimized planning approach for integrating photovoltaic as distributed generation (PV-DG) into the radial distribution power systems, utilizing exhaustive load flow (ELF), loss sensitivity factor (LSF), genetic algorithms (GA) methods, and numerical method based on LSF. The methodology aims to determine the optimal allocation and sizing of multiple PV-DG to minimize power loss through time series power flow analysis. An approach utilizing continuous sensitivity analysis is developed and inherently leverages power flow and loss equations to compute LSF of all buses in the system towards employing a dynamic PV-DG model for more accurate results. The algorithm uses a numerical grid search method to optimize PV-DG placement in a power distribution system, focusing on minimizing system losses. It combines iterative analysis, sensitivity assessment, and comprehensive visualization to identify and present the optimal PV-DG configurations. The present-ed algorithms are verified through co-simulation framework combining MATLAB and OpenDSS to carry out analysis for 12-bus radial distribution test system. The proposed numerical method is compared with other algorithms, such as ELF, LSF methods, and Genetic Algorithms (GA). Results show that the proposed numerical method performs well in comparison with LSF and ELF solutions. 展开更多
关键词 Photovoltaic Systems Distributed Generation Multiple Allocation and Sizing Power losses Radial Distribution System Genetic algorithm
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An Optimization Method for Reducing Losses in Distribution Networks Based on Tabu Search Algorithm
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作者 Jiaqian Zhao Xiufang Gu +1 位作者 Xiaoyu Wei Mingyu Bao 《Journal of Electronic Research and Application》 2025年第2期181-190,共10页
With the continuous growth of power demand and the diversification of power consumption structure,the loss of distribution network has gradually become the focus of attention.Given the problems of single loss reductio... With the continuous growth of power demand and the diversification of power consumption structure,the loss of distribution network has gradually become the focus of attention.Given the problems of single loss reduction measure,lack of economy,and practicality in existing research,this paper proposes an optimization method of distribution network loss reduction based on tabu search algorithm and optimizes the combination and parameter configuration of loss reduction measure.The optimization model is developed with the goal of maximizing comprehensive benefits,incorporating both economic and environmental factors,and accounting for investment costs,including the loss of power reduction.Additionally,the model ensures that constraint conditions such as power flow equations,voltage deviations,and line transmission capacities are satisfied.The solution is obtained through a tabu search algorithm,which is well-suited for solving nonlinear problems with multiple constraints.Combined with the example of 10kV25 node construction,the simulation results show that the method can significantly reduce the network loss on the basis of ensuring the economy and environmental protection of the system,which provides a theoretical basis for distribution network planning. 展开更多
关键词 Distribution network loss reduction measures ECONOMY Optimization model Tabu search algorithm
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Methodology for Detecting Non-Technical Energy Losses Using an Ensemble of Machine Learning Algorithms
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作者 Irbek Morgoev Roman Klyuev Angelika Morgoeva 《Computer Modeling in Engineering & Sciences》 2025年第5期1381-1399,共19页
Non-technical losses(NTL)of electric power are a serious problem for electric distribution companies.The solution determines the cost,stability,reliability,and quality of the supplied electricity.The widespread use of... Non-technical losses(NTL)of electric power are a serious problem for electric distribution companies.The solution determines the cost,stability,reliability,and quality of the supplied electricity.The widespread use of advanced metering infrastructure(AMI)and Smart Grid allows all participants in the distribution grid to store and track electricity consumption.During the research,a machine learning model is developed that allows analyzing and predicting the probability of NTL for each consumer of the distribution grid based on daily electricity consumption readings.This model is an ensemble meta-algorithm(stacking)that generalizes the algorithms of random forest,LightGBM,and a homogeneous ensemble of artificial neural networks.The best accuracy of the proposed meta-algorithm in comparison to basic classifiers is experimentally confirmed on the test sample.Such a model,due to good accuracy indicators(ROC-AUC-0.88),can be used as a methodological basis for a decision support system,the purpose of which is to form a sample of suspected NTL sources.The use of such a sample will allow the top management of electric distribution companies to increase the efficiency of raids by performers,making them targeted and accurate,which should contribute to the fight against NTL and the sustainable development of the electric power industry. 展开更多
关键词 Non-technical losses smart grid machine learning electricity theft FRAUD ensemble algorithm hybrid method forecasting classification supervised learning
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Adaptive Meta-Loss Networks:Learning Task-Agnostic Loss Functions via Evolutionary Optimization
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作者 Mirna Yunita Xiabi Liu +1 位作者 Zhaoyang Hai Rachmat Muwardi 《Computers, Materials & Continua》 2026年第5期1931-1949,共19页
Designing appropriate loss functions is critical to the success of supervised learning models.However,most conventional losses are fixed and manually designed,making them suboptimal for diverse and dynamic learning sc... Designing appropriate loss functions is critical to the success of supervised learning models.However,most conventional losses are fixed and manually designed,making them suboptimal for diverse and dynamic learning scenarios.In this work,we propose an Adaptive Meta-Loss Network(Adaptive-MLN)that learns to generate taskagnostic loss functions tailored to evolving classification problems.Unlike traditional methods that rely on static objectives,Adaptive-MLN treats the loss function itself as a trainable component,parameterized by a shallow neural network.To enable flexible,gradient-free optimization,we introduce a hybrid evolutionary approach that combines GeneticAlgorithms(GA)for global exploration and Evolution Strategies(ES)for local refinement.This co-evolutionary process dynamically adjusts the loss landscape,improvingmodel generalization without relying on analytic gradients or handcrafted heuristics.Experimental evaluations on synthetic tasks and the CIFAR-10 andMNIST datasets demonstrate that our approach consistently outperforms standard losses such as Cross-Entropy and Mean Squared Error in terms of accuracy,convergence,and adaptability. 展开更多
关键词 META-LEARNING adaptive loss function task-agnostic optimization evolutionary strategy genetic algorithm CLASSIFICATION
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Algorithmically Enhanced Data-Driven Prediction of Shear Strength for Concrete-Filled Steel Tubes
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作者 Shengkang Zhang Yong Jin +5 位作者 Soon Poh Yap Haoyun Fan Shiyuan Li Ahmed El-Shafie Zainah Ibrahim Amr El-Dieb 《Computer Modeling in Engineering & Sciences》 2026年第1期374-398,共25页
Concrete-filled steel tubes(CFST)are widely utilized in civil engineering due to their superior load-bearing capacity,ductility,and seismic resistance.However,existing design codes,such as AISC and Eurocode 4,tend to ... Concrete-filled steel tubes(CFST)are widely utilized in civil engineering due to their superior load-bearing capacity,ductility,and seismic resistance.However,existing design codes,such as AISC and Eurocode 4,tend to be excessively conservative as they fail to account for the composite action between the steel tube and the concrete core.To address this limitation,this study proposes a hybrid model that integrates XGBoost with the Pied Kingfisher Optimizer(PKO),a nature-inspired algorithm,to enhance the accuracy of shear strength prediction for CFST columns.Additionally,quantile regression is employed to construct prediction intervals for the ultimate shear force,while the Asymmetric Squared Error Loss(ASEL)function is incorporated to mitigate overestimation errors.The computational results demonstrate that the PKO-XGBoost model delivers superior predictive accuracy,achieving a Mean Absolute Percentage Error(MAPE)of 4.431%and R2 of 0.9925 on the test set.Furthermore,the ASEL-PKO-XGBoost model substantially reduces overestimation errors to 28.26%,with negligible impact on predictive performance.Additionally,based on the Genetic Algorithm(GA)and existing equation models,a strength equation model is developed,achieving markedly higher accuracy than existing models(R^(2)=0.934).Lastly,web-based Graphical User Interfaces(GUIs)were developed to enable real-time prediction. 展开更多
关键词 Asymmetric squared error loss genetic algorithm machine learning pied kingfisher optimizer quantile regression
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Multi-Dimensional Collaborative Optimization Strategy for Control Parameters of Thermal-Energy Storage Integrated Systems Considering Frequency Regulation Losses
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作者 Zezhong Liu Jinyu Guo +1 位作者 Xingxu Zhu Junhui Li 《Energy Engineering》 2026年第3期361-390,共30页
With the increasing penetration of renewable energy,the coordination of energy storage with thermal power for frequency regulation has become an effective means to enhance grid frequency security.Addressing the challe... With the increasing penetration of renewable energy,the coordination of energy storage with thermal power for frequency regulation has become an effective means to enhance grid frequency security.Addressing the challenge of improving the frequency regulation performance of a thermal-storage primary frequency regulation system while reducing its associated losses,this paper proposes a multi-dimensional cooperative optimization strategy for the control parameters of a combined thermal-storage system,considering regulation losses.First,the frequency regulation losses of various components within the thermal power unit are quantified,and a calculation method for energy storage regulation loss is proposed,based on Depth of Discharge(DOD)and C-rate.Second,a thermal-storage cooperative control method based on series compensation is developed to improve the system’s frequency regulation performance.Third,targeting system regulation loss cost and regulation output,and considering constraints on output overshoot and system parameters,an improved Particle Swarm Optimization(PSO)algorithm is employed to tune the parameters of the low-pass filter and the series compensator,thereby reducing regulation losses while enhancing performance.Finally,simulation results demonstrate that the total loss cost of the proposed control strategy is comparable to that of a system with only thermal power participation.However,the thermal power loss cost is reduced by 42.16%compared to the thermal-only case,while simultaneously improving system frequency stability.Thus,the proposed strategy effectively balances system frequency stability and economic efficiency. 展开更多
关键词 Frequency regulation losses of thermal power units energy storage frequency regulation losses series compensation enhanced particle swarm optimization algorithm primary frequency regulation
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Using Audiometric Data to Weigh and Prioritize Factors that Affect Workers’ Hearing Loss through Support Vector Machine (SVM) Algorithm 被引量:3
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作者 Hossein ElahiShirvan MohammadReza Ghotbi-Ravandi +1 位作者 Sajad Zare Mostafa Ghazizadeh Ahsaee 《Sound & Vibration》 EI 2020年第2期99-112,共14页
Workers’exposure to excessive noise is a big universal work-related challenges.One of the major consequences of exposure to noise is permanent or transient hearing loss.The current study sought to utilize audiometric... Workers’exposure to excessive noise is a big universal work-related challenges.One of the major consequences of exposure to noise is permanent or transient hearing loss.The current study sought to utilize audiometric data to weigh and prioritize the factors affecting workers’hearing loss based using the Support Vector Machine(SVM)algorithm.This cross sectional-descriptive study was conducted in 2017 in a mining industry in southeast Iran.The participating workers(n=150)were divided into three groups of 50 based on the sound pressure level to which they were exposed(two experimental groups and one control group).Audiometric tests were carried out for all members of each group.The study generally entailed the following steps:(1)selecting predicting variables to weigh and prioritize factors affecting hearing loss;(2)conducting audiometric tests and assessing permanent hearing loss in each ear and then evaluating total hearing loss;(3)categorizing different types of hearing loss;(4)weighing and prioritizing factors that affect hearing loss based on the SVM algorithm;and(5)assessing the error rate and accuracy of the models.The collected data were fed into SPSS 18,followed by conducting linear regression and paired samples t-test.It was revealed that,in the first model(SPL<70 dBA),the frequency of 8 KHz had the greatest impact(with a weight of 33%),while noise had the smallest influence(with a weight of 5%).The accuracy of this model was 100%.In the second model(70<SPL<80 dBA),the frequency of 4 KHz had the most profound effect(with a weight of 21%),whereas the frequency of 250 Hz had the lowest impact(with a weight of 6%).The accuracy of this model was 100%too.In the third model(SPL>85 dBA),the frequency of 4 KHz had the highest impact(with a weight of 22%),while the frequency of 250 Hz had the smallest influence(with a weight of 3%).The accuracy of this model was 100%too.In the fourth model,the frequency of 4 KHz had the greatest effect(with a weight of 24%),while the frequency of 500 Hz had the smallest effect(with a weight of 4%).The accuracy of this model was found to be 94%.According to the modeling conducted using the SVM algorithm,the frequency of 4 KHz has the most profound effect on predicting changes in hearing loss.Given the high accuracy of the obtained model,this algorithm is an appropriate and powerful tool to predict and model hearing loss. 展开更多
关键词 Noise modeling hearing loss data mining support vector machine algorithm
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Fuzzy-GA based algorithm for optimal placement and sizing of distribution static compensator (DSTATCOM) for loss reduction of distribution network considering reconfiguration 被引量:1
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作者 Mohammad Mohammadi Mahyar Abasi A.Mohammadi Rozbahani 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第2期245-258,共14页
This work presents a fuzzy based methodology for distribution system feeder reconfiguration considering DSTATCOM with an objective of minimizing real power loss and operating cost. Installation costs of DSTATCOM devic... This work presents a fuzzy based methodology for distribution system feeder reconfiguration considering DSTATCOM with an objective of minimizing real power loss and operating cost. Installation costs of DSTATCOM devices and the cost of system operation, namely, energy loss cost due to both reconfiguration and DSTATCOM placement, are combined to form the objective function to be minimized. The distribution system tie switches, DSTATCOM location and size have been optimally determined to obtain an appropriate operational condition. In the proposed approach, the fuzzy membership function of loss sensitivity is used for the selection of weak nodes in the power system for the placement of DSTATCOM and the optimal parameter settings of the DFACTS device along with optimal selection of tie switches in reconfiguration process are governed by genetic algorithm(GA). Simulation results on IEEE 33-bus and IEEE 69-bus test systems concluded that the combinatorial method using DSTATCOM and reconfiguration is preferable to reduce power losses to 34.44% for 33-bus system and to 45.43% for 69-bus system. 展开更多
关键词 distribution FACTS (DFACTS) distribution static compensator (DSTATCOM) network reconfiguration genetic algorithm fuzzy membership function power loss reduction
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Distributed Generators Location and Capacity Effect on Voltage Profile Improvement and Power Losses Reduction Using Genetic Algorithm
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作者 Mohamad Fawzy Kotb 《Journal of Energy and Power Engineering》 2012年第3期446-455,共10页
This paper presents a powerful approach to find the optimal size and location of distributed generation units in a distribution system using GA(Genetic Optimization algorithm).It is proved that GA method is fast and e... This paper presents a powerful approach to find the optimal size and location of distributed generation units in a distribution system using GA(Genetic Optimization algorithm).It is proved that GA method is fast and easy tool to enable the planners to select accurate and the optimum size of generators to improve the system voltage profile in addition to reduce the active and reactive power loss.GA fitness function is introduced including the active power losses,reactive power losses and the cumulative voltage deviation variables with selecting weight of each variable.GA fitness function is subjected to voltage constraints,active and reactive power losses constraints and DG size constraint. 展开更多
关键词 GA(genetic algorithm) DG(distributed generators) cumulative voltage deviation active and reactive power loss WEIGHT MATLAB load flow.
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Rail Line Detection Algorithm Based on Improved CLRNet
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作者 ZHOU Bowei XING Guanyu LIU Yanli 《Journal of Shanghai Jiaotong university(Science)》 2025年第5期923-934,共12页
In smart driving for rail transit,a reliable obstacle detection system is an important guarantee for the safety of trains.Therein,the detection of the rail area directly affects the accuracy of the system to identify ... In smart driving for rail transit,a reliable obstacle detection system is an important guarantee for the safety of trains.Therein,the detection of the rail area directly affects the accuracy of the system to identify dangerous targets.Both the rail line and the lane are presented as thin line shapes in the image,but the rail scene is more complex,and the color of the rail line is more difficult to distinguish from the background.By comparison,there are already many deep learning-based lane detection algorithms,but there is a lack of public datasets and targeted deep learning detection algorithms for rail line detection.To address this,this paper constructs a rail image dataset RailwayLine and labels the rail line for the training and testing of models.This dataset contains rich rail images including single-rail,multi-rail,straight rail,curved rail,crossing rails,occlusion,blur,and different lighting conditions.To address the problem of the lack of deep learning-based rail line detection algorithms,we improve the CLRNet algorithm which has an excellent performance in lane detection,and propose the CLRNet-R algorithm for rail line detection.To address the problem of the rail line being thin and occupying fewer pixels in the image,making it difficult to distinguish from complex backgrounds,we introduce an attention mechanism to enhance global feature extraction ability and add a semantic segmentation head to enhance the features of the rail region by the binary probability of rail lines.To address the poor curve recognition performance and unsmooth output lines in the original CLRNet algorithm,we improve the weight allocation for line intersection-over-union calculation in the original framework and propose two loss functions based on local slopes to optimize the model’s local sampling point training constraints,improving the model’s fitting performance on curved rails and obtaining smooth and stable rail line detection results.Through experiments,this paper demonstrates that compared with other mainstream lane detection algorithms,the algorithm proposed in this paper has a better performance for rail line detection. 展开更多
关键词 rail line detection attention mechanism semantic segmentation loss function CLRNet algorithm
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基于几何-语义约束与扩散增强的线描生成
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作者 贵向泉 张继续 +2 位作者 李立 李琪 张斌轩 《计算机技术与发展》 2026年第1期55-63,共9页
彩陶作为中国历史悠久的文物,具有重要的艺术与文化研究价值。针对彩陶线描生成中普遍存在的结构丢失、线条歪曲和细节模糊等问题,提出了一种双阶段高保真重构模型——GS-CycleDiff。以CycleGAN为基础,设计几何损失和语义损失,分别利用M... 彩陶作为中国历史悠久的文物,具有重要的艺术与文化研究价值。针对彩陶线描生成中普遍存在的结构丢失、线条歪曲和细节模糊等问题,提出了一种双阶段高保真重构模型——GS-CycleDiff。以CycleGAN为基础,设计几何损失和语义损失,分别利用MiDaS单目深度估计生成的伪深度图与原始照片深度图对齐,确保线描画在关键几何结构处的连贯性;并借助CLIP模型提取图像语义特征,通过最小化输入照片的CLIP和生成的线描画之间的距离,进行约束生成结果与原图在文化符号层面的对应关系。随后,将初步生成的线描画输入轻量级扩散去噪网络,通过多步迭代去噪和细节增强,抑制背景噪声、强化线条清晰度。实验结果表明,GS-CycleDiff生成的图像在线条清晰度、几何结构、语义一致性及整体视觉真实感方面,均显著优于传统CycleGAN模型及其他对比模型,并能在多种风格和复杂背景下生成精细的线描图像。 展开更多
关键词 线描画 CycleGAN GS-CycleDiff算法 几何损失 语义损失 扩散模型
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基于粒子群优化算法的分区式磁场调制电机多目标优化设计
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作者 吉敬华 王鹤 +1 位作者 赵文祥 凌志健 《电气工程学报》 北大核心 2026年第1期160-169,共10页
分区式磁场调制(Partitioned stator flux modulation,PSFM)电机气隙中含有丰富的谐波分量,不可避免产生较多铁耗。而凸极调制齿结构具有抑制铁损的作用,但也对电机其他性能产生一定影响,故采用基于粒子群优化算法的多目标优化设计以得... 分区式磁场调制(Partitioned stator flux modulation,PSFM)电机气隙中含有丰富的谐波分量,不可避免产生较多铁耗。而凸极调制齿结构具有抑制铁损的作用,但也对电机其他性能产生一定影响,故采用基于粒子群优化算法的多目标优化设计以得到性能最优的转子拓扑结构。通过分析永磁磁场与电枢反应磁场的谐波耦合过程,基于气隙磁场调制理论,揭示了电磁转矩产生机理。同时,研究了凸极调磁块对电机电磁性能的影响,探明了该拓扑结构在非工作谐波抑制方面的优势。其次,根据转子调磁环拓扑结构参数,以平均转矩、铁耗和转矩脉动为设计目标,结合响应面模型(Response surface methodology,RSM)和粒子群优化算法(Particle swarm optimization,PSO)进行了多目标优化设计。此外,基于有限元仿真,比较了优化前后分区式磁场调制电机的电磁性能,表明所采用方法具有良好的铁损抑制效果。最后,制作了样机并进行测试,验证了理论分析的正确性。 展开更多
关键词 分区式磁场调制电机 气隙磁场调制 铁损 多目标优化设计 粒子群优化算法
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面向城市配电网应急供电的电动汽车调度策略
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作者 胡长斌 李昊轩 +3 位作者 罗珊娜 李学成 李学斌 曹云涛 《电工技术》 2026年第3期67-74,共8页
城市电网负荷用电规模大、分布密集,一旦停电就会造成大量的经济损失,因此亟需提升其应急供电能力。同时,我国电动汽车保有量逐年攀升,具有巨大的应急调度潜力。为此,提出一种面向城市配电网应急供电逐级恢复的电动汽车优化调度策略。首... 城市电网负荷用电规模大、分布密集,一旦停电就会造成大量的经济损失,因此亟需提升其应急供电能力。同时,我国电动汽车保有量逐年攀升,具有巨大的应急调度潜力。为此,提出一种面向城市配电网应急供电逐级恢复的电动汽车优化调度策略。首先,建立电动汽车出行链以预测各区域的应急响应能力;其次,采用迪杰斯特拉算法计算充电站与各负荷间的最短电气距离,并结合功率数据划分供电恢复优先级顺位;最后,通过星雀优化算法得出失电全程经济总成本最小化、用户不便度最小化的结果,实现兼顾经济成本和用户需求的最优调度。采用北京市某实际住宅区配电网拓扑、某办公区配电网拓扑进行算例分析,验证了该方法的有效性。 展开更多
关键词 电动汽车出行链 应急调度 供电恢复 失电损失 星雀优化算法
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基于改进Informer模型的无人机姿态估计方法
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作者 肖蘅 包乃源 +1 位作者 周文 杨亚婷 《现代电子技术》 北大核心 2026年第4期57-63,共7页
传统无人机姿态估计方法由于传感器精度不高和设备成本限制,难以满足复杂环境中的精确需求。为此,提出一种基于改进Informer模型的无人机姿态估计方法,引入多尺度时间注意力机制和动态时间规整(DTW)损失函数,提升模型在长序列数据处理... 传统无人机姿态估计方法由于传感器精度不高和设备成本限制,难以满足复杂环境中的精确需求。为此,提出一种基于改进Informer模型的无人机姿态估计方法,引入多尺度时间注意力机制和动态时间规整(DTW)损失函数,提升模型在长序列数据处理和动态飞行数据适应方面的能力。此外,采用遗传算法对模型超参数进行优化,显著提高了复杂飞行数据处理的准确性和鲁棒性。基于苏黎世大学机器人实验室发布的UZH-FPV竞赛数据集,将改进后的Informer模型与LSTM、GRU和DNN模型进行了实验对比。结果表明,改进Informer模型在无人机的俯仰角、滚转角和偏航角估计方面均显著优于其他对比模型。 展开更多
关键词 无人机姿态估计 Informer模型 多尺度时间注意力机制 动态时间规整损失函数 遗传算法优化 长序列数据处理
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三维集成锥形TGV互连结构信号传输性能分析与优化
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作者 谭丽娟 黄根信 +1 位作者 黄春跃 李鹏 《电子元件与材料》 北大核心 2026年第2期173-179,共7页
玻璃通孔(Through Glass Via,TGV)是三维集成电路中重要的垂直互连结构。基于HFSS(High Frequency Structure Simulator)软件建立TGV电磁仿真模型,分析了信号频率、通孔最大直径、通孔高度、通孔最小直径对回波损耗(Return Loss,S11)的... 玻璃通孔(Through Glass Via,TGV)是三维集成电路中重要的垂直互连结构。基于HFSS(High Frequency Structure Simulator)软件建立TGV电磁仿真模型,分析了信号频率、通孔最大直径、通孔高度、通孔最小直径对回波损耗(Return Loss,S11)的影响。采用响应曲面法设计了17组试验仿真计算,构建了TGV结构参数与回波损耗S11的拟合模型,并结合遗传算法进行模型优化,最后通过仿真验证优化结果。结果表明:在1~10 GHz频段内,TGV的回波损耗S11随着信号频率增大而减小;随着通孔最大直径、通孔高度、通孔最小直径的增大而减小。各结构参数对S11的影响显著性排序为:通孔高度>最大通孔直径>最小通孔直径。最终得到TGV的最优参数组合为:通孔最大直径70μm、通孔高度400μm、通孔最小直径40μm。与基本模型相比,最优参数组合的回波损耗S11减小近18.87%,实现了锥形TGV的结构优化。 展开更多
关键词 玻璃通孔 回波损耗 结构参数 遗传算法 最优组合
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基于Ranking Loss的多标签分类集成学习算法 被引量:1
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作者 任志博 王莉莉 +2 位作者 付忠良 张丹普 杨燕霞 《计算机应用》 CSCD 北大核心 2013年第A01期40-42,68,共4页
针对目标可以属于多个类别的多标签分类问题,提出了一种基于Ranking Loss最小化的集成学习方法。算法基于Real AdaBoost算法的核心思想,从Ranking Loss定义出发,以Ranking Loss在样本空间最小化为目标,采取迭代的方法训练多个弱分类器,... 针对目标可以属于多个类别的多标签分类问题,提出了一种基于Ranking Loss最小化的集成学习方法。算法基于Real AdaBoost算法的核心思想,从Ranking Loss定义出发,以Ranking Loss在样本空间最小化为目标,采取迭代的方法训练多个弱分类器,并将这些弱分类器集成起来构成强分类器,强分类器的Ranking Loss随着弱分类器个数的增加而逐渐减少,并给出了算法流程。通过理论分析和实验数据对比验证了提出的多标签分类算法的有效性和稳定性。 展开更多
关键词 多标签分类 ADABOOST算法 Rankingloss 分类器组合 集成学习
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基于一维模型的进排气歧管多目标优化
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作者 李炜 许俊峰 +3 位作者 田永海 马富康 冯耀南 杨伟 《小型内燃机与车辆技术》 2026年第1期20-28,共9页
针对涡轮增压柴油机进气系统多参数协同优化问题,建立了一维热力学仿真模型,结合试验设计与多目标优化方法,实现了进排气歧管结构参数的协同优化。首先,基于容积法构建柴油机整机模型,通过对比不同工况下的功率、转矩及燃油消耗率试验数... 针对涡轮增压柴油机进气系统多参数协同优化问题,建立了一维热力学仿真模型,结合试验设计与多目标优化方法,实现了进排气歧管结构参数的协同优化。首先,基于容积法构建柴油机整机模型,通过对比不同工况下的功率、转矩及燃油消耗率试验数据,验证模型精度。进而以进气总管长度/管径、进气歧管长度/管径、排气总管/歧管体积为变量因子,采用D-optimal抽样法设计实验矩阵,在GT-Power平台开展DOE优化仿真。通过二阶响应面模型(Adj.R-sqr>0.8)以及主效应图验证了拟合精度并揭示进气歧管长度对油耗的显著负向影响(贡献度最高)及进气总管管径对功率/转矩/NO_(x)排放的正向主导作用。最后基于非归一化遗传算法,以最小化油耗与NO_(x)排放、最大化功率与转矩为目标进行多目标优化,获得Pareto最优解集,对比验证后,优化解集可靠且满足要求。 展开更多
关键词 发动机 气系统 管路优化 能量损失 遗传算法
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基于NSGA-Ⅱ算法的多腔室消声器结构优化
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作者 蔡紫晴 陈跃华 +2 位作者 郑佳晖 白杨 令狐世勋 《噪声与振动控制》 北大核心 2026年第1期281-287,共7页
针对多腔室消声器结构的优化问题,提出一种基于快速非支配排序的多腔室消声器多目标结构优化方法。首先,构建基于Chebyshev-变分法的多腔室消声器三维理论模型,并通过能量方程和瑞利-里兹法计算得到传递损失结果;其次,建立消声器传递损... 针对多腔室消声器结构的优化问题,提出一种基于快速非支配排序的多腔室消声器多目标结构优化方法。首先,构建基于Chebyshev-变分法的多腔室消声器三维理论模型,并通过能量方程和瑞利-里兹法计算得到传递损失结果;其次,建立消声器传递损失实验平台和有限元模型,将实验结果、有限元结果与计算结果进行对比验证;最后,采用快速非支配排序多目标遗传算法(NSGA-Ⅱ),对多腔室消声器的6个轴向参数和2个径向参数进行优化。结果表明:传递损失计算结果与有限元结果最大相对误差为2.12%,实验结果与计算结果在全频段范围内基本吻合,证明了多腔室消声器三维理论模型和求解方法的正确性。此外,得到以最大平均传递损失及传递损失和为目标的系列Pareto优化解集,并确定了可实现全频段内消声性能最优的多腔室消声器结构参数,优化后消声器的传递损失提高48.05 dB。以上研究可为多腔室消声器结构优化提供参考。 展开更多
关键词 声学 多腔室消声器 多目标优化算法 传递损失 结构优化
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基于不均衡样本的盾构结泥饼风险预测模型建立及实证
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作者 辛志勇 辛伟锁 +4 位作者 阳林 徐卫超 刘远 袁潇 王树英 《城市轨道交通研究》 北大核心 2026年第1期35-41,48,共8页
[目的]基于盾构机数据的刀盘结泥饼预测在保障隧道施工安全和提高施工效率方面有重要价值。传统机器学习模型在处理此类小样本数据时,难以有效捕捉少数类别特征,导致模型倾向于学习多数类别,而忽视少数类别,从而影响预警效果。对此,有... [目的]基于盾构机数据的刀盘结泥饼预测在保障隧道施工安全和提高施工效率方面有重要价值。传统机器学习模型在处理此类小样本数据时,难以有效捕捉少数类别特征,导致模型倾向于学习多数类别,而忽视少数类别,从而影响预警效果。对此,有必要基于不均衡样本建立盾构结泥饼风险预测模型并进行实证。[方法]首先,通过特征工程剔除停机数据并识别稳定掘进段;随后,结合特征重要度评估与相关性分析,筛选用于泥饼预测的关键特征;在此基础上,将Focal Loss(焦点损失)函数嵌入LSTM(长短期记忆网络),以增强模型对少数类样本的关注。以长春某地铁盾构实际工程为例对模型预测准确性进行实证。[结果及结论]面向EPB(土压平衡盾构)原始掘进数据的预处理流程框架有效提升了数据质量。通过正交试验,确定了焦点损失函数的最佳超参数组合为:调制指数γ=1.000,直实类别对应的类别权重α_(z)=0.750。在相同数据集和超参数条件下,传统LSTM模型的性能评估指标F_(1)值为0.724,而使用基于Focal Loss的LSTM模型后,F_(1)值提高至0.982,F_(1)值的增加表明Focal Loss函数的引入有效提升了模型对不平衡样本的预测性能。 展开更多
关键词 地铁 盾构施工 盾构泥饼预测 不均衡样本 长短期记忆网络算法 焦点损失函数
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基于改进YOLOv8的车辆漆面缺陷检测
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作者 郝友胜 文贞慧 +2 位作者 冯小溪 邓泽华 黄清宝 《计算机工程》 北大核心 2026年第4期252-263,共12页
针对车辆漆面缺陷检测精度低、检测算法参数量大、难易样本不均匀等问题,提出一种基于改进YOLOv8的车辆漆面检测算法。首先,为了提升划痕状缺陷检测能力并降低模型规模,将DAT(Deformable Attention Transformer)注意力机制引入主干网络... 针对车辆漆面缺陷检测精度低、检测算法参数量大、难易样本不均匀等问题,提出一种基于改进YOLOv8的车辆漆面检测算法。首先,为了提升划痕状缺陷检测能力并降低模型规模,将DAT(Deformable Attention Transformer)注意力机制引入主干网络来增强长距离特征依赖关系,同时使用幻影卷积(GhostConv)替换网络中的卷积(Conv)模块。然后,为了提升特征提取能力并进一步降低模型规模,结合FasterBlock模块与高效多尺度注意力(EMA)机制提出C2f-E(C2f Based on EMA)模块。接着,为了提高小目标检测性能,基于双向特征金字塔网络(BiFPN)进行设计,并增加小目标检测头与多尺度特征融合支路,提出BiFPN-D(BiFPN with Small Object Detection Head)颈部金字塔结构。最后,为了解决难易样本的平衡问题并提高针对小目标缺陷的检测性能,使用WIoUv3(Wise-Intersection over Union version 3)作为训练网络的损失函数。在自建的车辆漆面缺陷数据集上进行训练并开展对比实验。实验结果表明,相较于YOLOv8n,改进模型的均值平均精度(mAP@0.5)提高了5.5百分点、规模减小了1.4×106。 展开更多
关键词 YOLOv算法 车辆漆面缺陷 目标检测 双向特征金字塔网络 损失函数
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