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A Direct Algorithm Maple Package of One-Dimensional Optimal System for Group Invariant Solutions 认领 引用 被引量：1
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作者 Lin Zhang Zhong Han Yong Chen 《Communications in Theoretical Physics》 SCIE CAS CSCD 2018年第1期14-22,共9页
To construct the one-dimensional optimal system of finite dimensional Lie algebra automatically,we develop a new Maple package One Optimal System.Meanwhile,we propose a new method to calculate the adjoint transformati... To construct the one-dimensional optimal system of finite dimensional Lie algebra automatically,we develop a new Maple package One Optimal System.Meanwhile,we propose a new method to calculate the adjoint transformation matrix and find all the invariants of Lie algebra in spite of Killing form checking possible constraints of each classification.Besides,a new conception called invariance set is raised.Moreover,this Maple package is proved to be more efficiency and precise than before by applying it to some classic examples. 展开更多
关键词 symbolic computation mathematics mechanization direct algorithm optimal system
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RESEARCH OF PROBLEMS ON REALIZING DIRECT ALGORITHM OF WAVELET TRANSFORM 认领 引用 被引量：2
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作者 Tang BaopingZhong YoumingQin ShurenDepartment of Mechanical Engineering,Chongqing University,Chongqing 400044, China 《Chinese Journal of Mechanical Engineering》 EI CAS 2003年第2期136-140,共5页
Direct algorithm of wavelet transform (WT) is the numerical algorithmobtained from the integral formula of WT by directly digitization. Some problems on realizing thealgorithm are studied. Some conclusions on the dire... Direct algorithm of wavelet transform (WT) is the numerical algorithmobtained from the integral formula of WT by directly digitization. Some problems on realizing thealgorithm are studied. Some conclusions on the direct algorithm of discrete wavelet transform (DWT),such as discrete convolution operation formula of wavelet coefficients and wavelet components,sampling principle and technology to wavelets, deciding method for scale range of wavelets, measuresto solve edge effect problem, etc, are obtained. The realization of direct algorithm of continuouswavelet transform (CWT) is also studied. The computing cost of direct algorithm and Mallat algorithmof DWT are still studied, and the computing formulae are obtained. These works are beneficial todeeply understand WT and Mallat algorithm. Examples in the end show that direct algorithm can alsobe applied widely. 展开更多
关键词 wavelet transform direct algorithm mallat algorithm
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Well production optimization using streamline features-based objective function and Bayesian adaptive direct search algorithm 认领 引用 被引量：10
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作者 Qi-Hong Feng Shan-Shan Li +2 位作者 Xian-Min Zhang Xiao-Fei Gao Ji-Hui Ni 《Petroleum Science》 SCIE CAS CSCD 2022年第6期2879-2894,共16页
Well production optimization is a complex and time-consuming task in the oilfield development.The combination of reservoir numerical simulator with optimization algorithms is usually used to optimize well production.T... Well production optimization is a complex and time-consuming task in the oilfield development.The combination of reservoir numerical simulator with optimization algorithms is usually used to optimize well production.This method spends most of computing time in objective function evaluation by reservoir numerical simulator which limits its optimization efficiency.To improve optimization efficiency,a well production optimization method using streamline features-based objective function and Bayesian adaptive direct search optimization(BADS)algorithm is established.This new objective function,which represents the water flooding potential,is extracted from streamline features.It only needs to call the streamline simulator to run one time step,instead of calling the simulator to calculate the target value at the end of development,which greatly reduces the running time of the simulator.Then the well production optimization model is established and solved by the BADS algorithm.The feasibility of the new objective function and the efficiency of this optimization method are verified by three examples.Results demonstrate that the new objective function is positively correlated with the cumulative oil production.And the BADS algorithm is superior to other common algorithms in convergence speed,solution stability and optimization accuracy.Besides,this method can significantly accelerate the speed of well production optimization process compared with the objective function calculated by other conventional methods.It can provide a more effective basis for determining the optimal well production for actual oilfield development. 展开更多
关键词 Well production Optimization efficiency Streamline simulation Streamline feature Objective function Bayesian adaptive direct search algorithm
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Direct P-code acquisition algorithm based on bidirectional overlap technique 认领 引用 被引量：3
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作者 Ying Xu Lijuan Xu +1 位作者 Hong Yuan Ruidan Luo 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第4期538-546,共9页
According to the signal-to-noise ratio （SNR） loss of average algorithms in direct P-code acquisition method, this paper analyzes the SNR performance of the overlap average algorithm quantitatively, and derives the r... According to the signal-to-noise ratio （SNR） loss of average algorithms in direct P-code acquisition method, this paper analyzes the SNR performance of the overlap average algorithm quantitatively, and derives the relationship of SNR loss with overlap shift value and initial average phase difference in the overlap average algorithm. On this basis, the bidirectional overlap average algorithm based on optimal correlation SNR is proposed. The algorithm maintains SNR consistent in the entire initial average phase difference space, and has a better SNR performance than the overlap average algorithm. The effectiveness of the algorithm is verified by both theoretical analysis and simulation results. The SNR performance of the bidirectional overlap average algorithm is 5 dB better than that of the direct average algorithm, and 2 dB better than that of the overlap average algorithm, which provides the support for direct P-code acquisition in low SNR. 展开更多
关键词 P-code direct acquisition direct average algorithm,bidirectional overlap algorithm.
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Comparison between iterative wavefront control algorithm and direct gradient wavefront control algorithm for adaptive optics system 认领 引用 被引量：3
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作者 程生毅 刘文劲 +3 位作者 陈善球 董理治 杨平 许冰 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第8期391-397,共7页
Among all kinds of wavefront control algorithms in adaptive optics systems, the direct gradient wavefront control algorithm is the most widespread and common method. This control algorithm obtains the actuator voltage... Among all kinds of wavefront control algorithms in adaptive optics systems, the direct gradient wavefront control algorithm is the most widespread and common method. This control algorithm obtains the actuator voltages directly from wavefront slopes through pre-measuring the relational matrix between deformable mirror actuators and Hartmann wavefront sensor with perfect real-time characteristic and stability. However, with increasing the number of sub-apertures in wavefront sensor and deformable mirror actuators of adaptive optics systems, the matrix operation in direct gradient algorithm takes too much time, which becomes a major factor influencing control effect of adaptive optics systems. In this paper we apply an iterative wavefront control algorithm to high-resolution adaptive optics systems, in which the voltages of each actuator are obtained through iteration arithmetic, which gains great advantage in calculation and storage. For AO system with thousands of actuators, the computational complexity estimate is about O(n2) ～ O(n3) in direct gradient wavefront control algorithm, while the computational complexity estimate in iterative wavefront control algorithm is about O(n) ～(O(n)3/2), in which n is the number of actuators of AO system. And the more the numbers of sub-apertures and deformable mirror actuators, the more significant advantage the iterative wavefront control algorithm exhibits. 展开更多
关键词 adaptive optics iterative wavefront control algorithm direct gradient wavefront control algorithm
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Direction of Arrivals Estimation for Correlated Broadband Radio Signals by MVDR Algorithm Using Wavelet 认领 引用 被引量：4
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作者 Ying Liu Chi Xie Yourun Zhang 《China Communications》 SCIE CSCD 2017年第3期190-197,共8页
A theoretical relationship between the wavelet transform and the fast fourier transformation(FFT) methods in broadband wireless signal is proposed for solving the direction of arrivals(DOAs) estimation problem. This l... A theoretical relationship between the wavelet transform and the fast fourier transformation(FFT) methods in broadband wireless signal is proposed for solving the direction of arrivals(DOAs) estimation problem. This leads naturally to the derivation of minimum variance distortionless response(MVDR) algorithm, which combines the benefits of subspace methods with those of wavelet, and spatially smoothed versions are utilized which exhibits good performance against correlated signals. We test the method's performance by simulating and comparing the performance of proposed algorithm, FFT MVDR and MVDR with correlated signals, and an improved performance is obtained. 展开更多
关键词 array antenna broadband radio signal direction of arrival MVDR algorithm wavelet
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Directional Routing Algorithm for Deep Space Optical Network 认领 引用
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作者 Lei Guo Xiaorui Wang +3 位作者 Yejun Liu Pengchao Han Yamin Xie Yuchen Tan 《China Communications》 SCIE CSCD 2017年第1期158-168,共11页
With the development of science, economy and society, the needs for research and exploration of deep space have entered a rapid and stable development stage. Deep Space Optical Network(DSON) is expected to become an i... With the development of science, economy and society, the needs for research and exploration of deep space have entered a rapid and stable development stage. Deep Space Optical Network(DSON) is expected to become an important foundation and inevitable development trend of future deepspace communication. In this paper, we design a deep space node model which is capable of combining the space division multiplexing with frequency division multiplexing. Furthermore, we propose the directional flooding routing algorithm(DFRA) for DSON based on our node model. This scheme selectively forwards the data packets in the routing, so that the energy consumption can be reduced effectively because only a portion of nodes will participate the flooding routing. Simulation results show that, compared with traditional flooding routing algorithm(TFRA), the DFRA can avoid the non-directional and blind transmission. Therefore, the energy consumption in message routing will be reduced and the lifespan of DSON can also be prolonged effectively. Although the complexity of routing implementation is slightly increased compared with TFRA, the energy of nodes can be saved and the transmission rate is obviously improved in DFRA. Thus the overall performance of DSON can be significantly improved. 展开更多
关键词 deep space optical network routing algorithm directional flooding routing algorithm traditional flooding routing algorithm
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A ROBUST PHASE-ONLY DIRECT DATA DOMAIN ALGORITHM BASED ON GENERALIZED RAYLEIGH QUOTIENT OPTIMIZATION USING HYBRID GENETIC ALGORITHM 认领 引用 被引量：2
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作者 Shao Wei Qian Zuping Yuan Feng 《Journal of Electronics(China)》 2007年第4期560-566,共7页
A robust phase-only Direct Data Domain Least Squares (D3LS) algorithm based on gen- eralized Rayleigh quotient optimization using hybrid Genetic Algorithm (GA) is presented in this letter. The optimization efficiency ... A robust phase-only Direct Data Domain Least Squares (D3LS) algorithm based on gen- eralized Rayleigh quotient optimization using hybrid Genetic Algorithm (GA) is presented in this letter. The optimization efficiency and computational speed are improved via the hybrid GA com- posed of standard GA and Nelder-Mead simplex algorithms. First, the objective function, with a form of generalized Rayleigh quotient, is derived via the standard D3LS algorithm. It is then taken as a fitness function and the unknown phases of all adaptive weights are taken as decision variables. Then, the nonlinear optimization is performed via the hybrid GA to obtain the optimized solution of phase-only adaptive weights. As a phase-only adaptive algorithm, the proposed algorithm is sim- pler than conventional algorithms when it comes to hardware implementation. Moreover, it proc- esses only a single snapshot data as opposed to forming sample covariance matrix and operating matrix inversion. Simulation results show that the proposed algorithm has a good signal recovery and interferences nulling performance, which are superior to that of the phase-only D3LS algorithm based on standard GA. 展开更多
关键词 Generalized Rayleigh quotient Hybrid genetic algorithm Phase-only optimization Direct Data Domain Least Squares （D^3LS） algorithm Nelder-Mead simplex algorithm
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A Unified Approach Toward Simulating Constant and Varying Amplitude Fatigue Failure Effects of Metals with Fast and Efficient Algorithms 认领 引用 被引量：4
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作者 Si-Yu Wang Lin Zhan +1 位作者 Hui-Feng Xi Heng Xiao 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2021年第1期53-64,共12页
A new finite strain elastoplastic J2-flow model is established with an explicit formulation of work-hardening and softening effects up to eventual failure,in which both a new flow rule free of yielding and an asymptot... A new finite strain elastoplastic J2-flow model is established with an explicit formulation of work-hardening and softening effects up to eventual failure,in which both a new flow rule free of yielding and an asymptotically vanishing stress limit are incorporated.The novelties of this new model are as follows:(i)Fatigue failure effects under repeated loading conditions with either constant or varying amplitudes are automatically characterized as inherent response features;(ii)neither additional damage-like variables nor failure criteria need to be involved;and(iii)both high-and low-cycle fatigue effects may be simultaneously treated.A fast and efficient algorithm of high accuracy is proposed for directly simulating high-and medium-high-cycle fatigue failure effects under repeated loading conditions.Toward this goal,a direct and explicit relationship between the fatigue life and the stress amplitude is obtained by means of explicit and direct procedures of integrating the coupled elastoplastic rate equations for any given number of loading-unloading cycles with varying stress amplitudes.Numerical examples suggest that the new algorithm is much more fast and efficient than usual tedious and very time-consuming integration procedures. 展开更多
关键词 Metals Finite strain Elastoplasticity Fatigue failure Direct algorithm
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基于自适应直接二进制搜索算法的超紧凑型8通道模式-偏振复用器 认领 引用 被引量：1
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作者 马汉斯 林振 +9 位作者 何新 侯海良 李雪垒 贺龙辉 甘龙飞 赵娜 许辉 周灵钧 吴加贵 杨俊波 《物理学报》 SCIE EI CAS CSCD 北大核心 2026年第4期243-252,共10页
针对模式复用器难以兼容低损耗、小尺寸、多通道的难题,本文结合数字结构与波导结构,设计、加工、测试了一种超紧凑8通道模式-偏振复用器,以大幅度提升光互连的集成度和传输容量.数字结构是由新颖的自适应直接二进制搜索(adaptive direc... 针对模式复用器难以兼容低损耗、小尺寸、多通道的难题,本文结合数字结构与波导结构,设计、加工、测试了一种超紧凑8通道模式-偏振复用器,以大幅度提升光互连的集成度和传输容量.数字结构是由新颖的自适应直接二进制搜索(adaptive direct binary search,ADBS)算法优化,用于TE0,TE1,TE2和TE3模式的复用和解复用.ADBS算法通过引入池化算子和变异算子可以自适应地调节局部收敛,在保障器件小尺寸的前提下,大幅降低优化时间成本.波导结构是由非对称定向耦合器(asymmetrical directional coupler,ADC)设计,用于TM1,TM2,TM3和TM4模式的复用和解复用.ADC结构通过级联策略,在数字结构的基础上,进一步扩展通道数量.基于现有研究来看,所设计数字-波导结构有效长度约为100μm,是尺寸最小的8通道复用器.测试结果显示,在1550 nm处,测量的插入损耗和串扰分别小于1.2 dB和-12.5 dB.同时,在1540—1560 nm波长内,插入损耗和串扰分别小于1.7 dB和-9.3 dB.此外,在256 Gbps(1 Gbps=125 MB/s)数据传输实验中,测试所得眼图呈现出清晰且开放的特征,直观地反映出该器件具有优异的数据传输能力. 展开更多
关键词 8通道模式-偏振复用器 自适应直接二进制搜索算法 非对称定向耦合器
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分布式光伏电源直供电监控策略研究 认领 引用 被引量：1
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作者 陈石东 杨帅 +2 位作者 贺星 余敏琪 黄瑞 《电力科学与技术学报》 CAS CSCD 北大核心 2026年第2期201-211,共11页
分布式光伏电源的出力的随机性与间歇性对配电网的稳定运行及电能质量提出了显著挑战。对此,提出一种基于近邻传播聚类算法(affinity propagation clustering algorithm,APCA)的方法,有效识别光伏电源的直供电情况。与传统方法不同,该... 分布式光伏电源的出力的随机性与间歇性对配电网的稳定运行及电能质量提出了显著挑战。对此,提出一种基于近邻传播聚类算法(affinity propagation clustering algorithm,APCA)的方法,有效识别光伏电源的直供电情况。与传统方法不同,该方法选择同台区的光伏电源,降低气候和光照强度等因素的影响,提高算法准确性和可操作性。首先,采用相关系数筛,选出相关性较高的光伏电源。其次,利用近邻传播聚类算法(affinity propagation,AP)对三相并网功率曲线进行聚类分析,进一步识别直供电嫌疑并确定可能的直供电类型。最后,采用案例分析,验证所提方法可帮助供电公司更好地管理分布式光伏电源系统,提高电力市场的公平性和透明度。 展开更多
关键词 分布式电源 近邻传播聚类算法 直供电 相关性分析
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VMD-IFDA-NAHL模型在某水文站日径流预测中的应用 认领 引用
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作者 丁公博 王超 +1 位作者 徐宇萱 许珂 《南水北调与水利科技（中英文）》 CAS CSCD 北大核心 2026年第3期554-561,共8页
为提升水资源科学化管理水平,增强洪水灾害预防能力,构建一种基于变分模态分解-改进流向算法-具有增强隐含层的自动神经网络模型(variational mode decomposition-improved flow direction algorithm-network with an augmented hidden ... 为提升水资源科学化管理水平,增强洪水灾害预防能力,构建一种基于变分模态分解-改进流向算法-具有增强隐含层的自动神经网络模型(variational mode decomposition-improved flow direction algorithm-network with an augmented hidden layer,VMD-IFDA-NAHL)的日径流预测模型,该模型运用变分模态分解技术对某水文站的日径流数据进行预处理,去除径流数据中存在的噪声并提取日径流数据中潜在的非线性特征;采用改进流向算法对具有增强隐藏层的自动神经网络模型进行优化,提高模型对径流变化的捕捉能力和预测精度。同时,以某水文站为例,开展VMD-IFDA-NAHL预测模型与对比模型日径流预测的研究。结果表明:VMD-IFDA-NAHL模型在径流预测的准确性、稳定性和泛化能力方面均优于对比模型,显示出在径流预测领域的广阔应用潜力。构建的日径流预测模型可以为水资源管理、防洪调控等提供可靠的、科学的数据支撑。 展开更多
关键词 日径流预测 自动神经网络 变分模态分解 流向算法 改进径流算法
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基于直接校正算法与分数阶微分定量反演矿区土壤Pb和Zn含量 认领 引用
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作者 杞应涛 甘淑 +3 位作者 袁希平 胡琳 胡建开 卢成卓 《土壤学报》 CAS CSCD 北大核心 2026年第1期241-250,共10页
高光谱技术为土壤重金属含量的快速、精准监测提供了全新的解决方案。然而,利用实验室光谱建立的模型在实际应用中泛化能力较弱;此外,直接使用遥感影像光谱数据反演土壤重金属含量时,受成像时天气状况以及地面环境等因素的影响,导致模... 高光谱技术为土壤重金属含量的快速、精准监测提供了全新的解决方案。然而,利用实验室光谱建立的模型在实际应用中泛化能力较弱;此外,直接使用遥感影像光谱数据反演土壤重金属含量时,受成像时天气状况以及地面环境等因素的影响,导致模型精度较低,难以准确反映研究区重金属含量的分布情况。本研究以云南省会泽县矿山镇某尾矿区为研究对象,获取56个表层土壤样本的高光谱反射率(地面和影像)以及Pb、Zn的含量。首先,采用直接校正(DS)算法结合实验室光谱数据对高分5号影像数据进行光谱校正;随后,使用Box-Cox变换对Pb和Zn含量进行正态化处理;接着,通过分数阶微分(FOD)对校正后的光谱进行变换,并利用Boruta算法筛选特征波段;最后,构建随机森林和XGBoost反演模型。研究结果表明,DS算法可有效消除土壤粒径和含水量等干扰因素对影像光谱的影响;Box-Cox变换解决了Pb和Zn含量的偏态分布问题;FOD有效增强了细节光谱特征,Boruta算法选出的特征波段显著提升了反演精度。此外,XGBoost模型在处理复杂特征交互和非线性关系的回归问题时,展现出更高的预测精度。在该研究区Pb含量的最佳反演模型为0.8 Order-Boruta-XGBoost,Zn含量的最佳反演模型为1.6 Order-Boruta-XGBoost,两个最佳反演模型具有较好的鲁棒性。本研究为利用高光谱技术反演矿区土壤中Pb和Zn含量提供了可靠的参考方法。 展开更多
关键词 土壤高光谱 重金属 分数阶微分 直接校正算法 XGBoost模型
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基于SCSSA-BiLSTM的变压器故障诊断模型 认领 引用 被引量：2
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作者 汪繁荣 李州 《南方电网技术》 CSCD 北大核心 2026年第2期78-86,共9页
针对变压器故障诊断存在诊断精度不高和麻雀搜索算法(sparrow search algorithm,SSA)存在易陷入局部最优的问题,提出了一种基于融合正余弦和柯西变异的麻雀搜索算法(sine-cosine and Cauchy mutation sparrow search algorithm,SCSSA)... 针对变压器故障诊断存在诊断精度不高和麻雀搜索算法(sparrow search algorithm,SSA)存在易陷入局部最优的问题,提出了一种基于融合正余弦和柯西变异的麻雀搜索算法(sine-cosine and Cauchy mutation sparrow search algorithm,SCSSA)优化双向长短期记忆网络(bi-directional long-short term memory,BiLSTM)的变压器故障诊断模型。首先,基于油中溶解气体分析(dissolved gas analysis,DGA)法,以5种特征量作为输入,其次利用正余弦策略和柯西变异策略对麻雀算法进行改进,然后将SCSSA算法、SSA算法和灰狼优化算法(grey wolf optimizer,GWO)在4种测试函数上进行性能对比,验证了SCSSA算法的优越性。最后利用SCSSA算法对BiLSTM网络中的参数进行优化,从而提高BiLSTM网络在变压器故障诊断中的性能。实验结果表明,所提SCSSA-BiLSTM故障诊断模型的综合诊断精度为95.1%,相比于SSA-BiLSTM、GWO-BiLSTM、BiLSTM和LSTM模型分别提高了7.3%、12.2%、14.6%、19.5%,并且SCSSA-BiLSTM模型有着更好的鲁棒性。 展开更多
关键词 变压器 故障诊断 麻雀搜索算法 双向长短期记忆网络 诊断精度
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基于动态分布式有向图的记忆建模 认领 引用
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作者 危辉 冯辰越 《计算机科学》 CSCD 北大核心 2026年第5期247-256,共10页
记忆机制研究是计算神经科学中的核心课题。虽然已有研究揭示了神经元网络中的突触可塑性和信号传递等对记忆形成的重要性,但在计算模型中精准再现这些复杂的生物学机制依然面临巨大挑战。现有的传统图论模型能够描述神经网络的拓扑结构... 记忆机制研究是计算神经科学中的核心课题。虽然已有研究揭示了神经元网络中的突触可塑性和信号传递等对记忆形成的重要性,但在计算模型中精准再现这些复杂的生物学机制依然面临巨大挑战。现有的传统图论模型能够描述神经网络的拓扑结构,但其静态特性和集中化的信息处理方式无法充分模拟生物神经网络的动态性、分布式和去中心化特征。因此,亟需提出更符合生物神经系统特征的基于动态有向图的记忆模型。该模型基于记忆印迹理论,采用稀疏连接的有向图网络结构,通过局部信息进行自主决策,实现去中心化的并行处理,创新性地引入了可变电阻结构,动态调整电阻值以模拟神经元突触的可塑性,并通过资源竞争的路径强化机制模仿生物神经网络的记忆过程。实验结果表明,该模型在不同规模和拓扑结构下均能稳定实现记忆功能,且记忆容量随网络宽度的增加呈近似线性增长,表现出与生物神经网络相似的特征。与现有主流模型相比,所提模型在资源利用效率、记忆容量及网络扩展性等方面具有显著优势,为类脑计算系统的设计与智能系统的研发提供了坚实的理论基础。 展开更多
关键词 记忆建模 分布式算法 有向图
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基于改进DBS算法的三波长消色差透镜设计 认领 引用
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作者 蔡吉祥 胡成宇 +1 位作者 李玮 张婷婷 《光电工程》 CAS CSCD 北大核心 2026年第5期69-81,共13页
传统衍射透镜受限于材料的固有特性,存在聚焦效率低、工作波长单一和色差等问题,常通过多个透镜级联提高成像质量,限制了光学系统的小型化与集成化发展。多台阶微透镜为光学系统的微型化提供了新思路,然而仍受到色差等影响且设计较为复... 传统衍射透镜受限于材料的固有特性,存在聚焦效率低、工作波长单一和色差等问题,常通过多个透镜级联提高成像质量,限制了光学系统的小型化与集成化发展。多台阶微透镜为光学系统的微型化提供了新思路,然而仍受到色差等影响且设计较为复杂。为此,本文提出一种基于改进直接二进制搜索算法的三波长消色差透镜设计方法,在1.064μm、1.300μm和1.550μm三波长下实现了高效率消色差。理论结果表明,优化后的八台阶、十六台阶透镜的平均聚焦效率分别达到90.99%和92.46%,相较于优化前分别提升了13.95%和13.64%。该方法可用于三波长成像系统、光计算与光信息处理和生物医学成像等领域。 展开更多
关键词 三波长 直接二进制搜索算法 消色差 高效率 衍射透镜
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逆向设计的偏振不敏感2×2交叉波导 认领 引用
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作者 马汉斯 林振 +5 位作者 孙樊 肖韵 肖海川 赵娜 甘龙飞 杨俊波 《光子学报》 EI CAS CSCD 北大核心 2026年第6期215-224,共10页
针对光子集成电路中交叉波导的偏振敏感性强及集成密度低的问题,基于多模干涉原理,利用直接二进制搜索算法,优化了偏振不敏感的2×2交叉波导,包括双偏振(Dual-polarization Waveguide Crossing,DP-WC)、TM0偏振(Fundamental Tran... 针对光子集成电路中交叉波导的偏振敏感性强及集成密度低的问题,基于多模干涉原理,利用直接二进制搜索算法,优化了偏振不敏感的2×2交叉波导,包括双偏振(Dual-polarization Waveguide Crossing,DP-WC)、TM0偏振(Fundamental Transverse Magnetic Waveguide Crossing,TM0-WC)及TE0偏振(Fundamental Transverse Electric Waveguide Crossing,TE0-WC)交叉波导。交叉波导的尺寸皆为4.8μm×4.8μm。加工器件的表征结果表明,DP-WC支持TE0和TM0模式,在1540 nm到1560 nm带宽范围内,TE0模式的插入损耗(Insertion Loss,IL)和消光比(Extinction Ratio,ER)分别小于1.3 dB和大于14 dB,TM0模式的IL和ER分别小于1.2 dB和大于13.4 dB,而偏振相关损耗(Polarization Dependent Loss,PDL)PDL小于0.1 dB;TM0-WC支持TM0模式而抑制TE0模式,在1540 nm到1560 nm带宽范围内,TM0模式的IL和ER分别小于1 dB和大于14.9 dB,TE0模式的IL和ER分别大于12 dB和大于2 dB,而PDL大于11 dB;TE0-WC支持TE0模式而抑制TM0模式,在1540 nm到1560 nm带宽范围内,TE0模式的IL和ER小于2.4 dB和大于14.6 dB,TM0模式的IL和ER分别大于10.7 dB和大于5.1 dB,而PDL大于8.3 dB。 展开更多
关键词 光子集成电路 偏振不敏感的交叉波导 多模干涉 直接二进制搜索算法
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改进NGO优化MVMD-BiLSTM的锂电池剩余使用寿命预测 认领 引用 被引量：4
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作者 郭喜峰 黄裕海 +2 位作者 单丹 原宝龙 宁一 《电源学报》 CSCD 北大核心 2026年第4期158-168,共11页
为解决锂电池剩余使用寿命RUL(remaining useful life)预测过程中存在的噪声干扰、容量增生导致模型预测精度低的问题,提出1种将参数优化后的多元变分模态分解MVMD(multivariate variational modal decomposition)和双向长短期记忆BiLST... 为解决锂电池剩余使用寿命RUL(remaining useful life)预测过程中存在的噪声干扰、容量增生导致模型预测精度低的问题,提出1种将参数优化后的多元变分模态分解MVMD(multivariate variational modal decomposition)和双向长短期记忆BiLSTM(bi-directional long and short-term memory)网络相结合的RUL预测方法。从锂电池充放电过程中提取多个健康因子HF(health factor)作为模型输入,将正余弦优化算法和鲸鱼螺旋捕食机制结合引进北方苍鹰优化算法,利用其对MVMD参数寻优。然后利用寻优后的MVMD分解HF为若干个平稳分量,最后利用寻优后的多层BiLSTM进行预测,叠加求和得出最终RUL结果。应用NASA和CALCE数据集与其他方法进行对比分析,结果表明所提方法具有更高的预测精度和泛化适应性。 展开更多
关键词 锂电池 剩余使用寿命预测 多元变分模态分解 改进北方苍鹰优化算法 双向长短期记忆网络
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多策略改进河马算法的BiGRU滚动轴承寿命预测 认领 引用
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作者 周玉 陈博 +2 位作者 杨凯月 白磊 张佳硕 《哈尔滨工业大学学报》 EI CAS CSCD 北大核心 2026年第4期83-94,共12页
为更加精准地预测滚动轴承剩余寿命,提出一种基于多策略改进河马优化(TOBCHO)算法与双向门控循环单元(BiGRU)融合的轴承寿命预测方法。首先,对全寿命周期信号进行特征提取,通过构建基于相关性、单调性和鲁棒性综合评价指标,筛选出敏感... 为更加精准地预测滚动轴承剩余寿命,提出一种基于多策略改进河马优化(TOBCHO)算法与双向门控循环单元(BiGRU)融合的轴承寿命预测方法。首先,对全寿命周期信号进行特征提取,通过构建基于相关性、单调性和鲁棒性综合评价指标,筛选出敏感特征向量作为敏感特征集,并采用主成分分析(PCA)技术构建健康指标曲线。其次,针对BiGRU在滚动轴承寿命预测研究超参数难以确定的问题,提出多策略改进河马算法优化BiGRU的寿命预测模型(TOBCHO-BiGRU),该模型在河马算法种群初始化阶段引入最优最差对立学习机制,生成对立解扩展搜索空间;采用混沌映射序列替代传统随机数的生成方式以解决算法收敛不稳定的问题;在HO迭代后期引入最优个体自适应分布扰动策略,通过动态调整扰动强度以实现局部开发与全局搜索能力的平衡。最后,通过在国际通用的IEEE PHM 2012轴承数据集上进行实验验证,并与其他多种预测模型进行对比分析,结果充分证明了所提TOBCHO-BiGRU方法在预测精度方面具有显著优势。消融实验结果表明,各改进策略之间存在正向协同效应,共同促进河马优化算法性能的提升,为复杂工况下的滚动轴承寿命预测提供了高精度解决方案。 展开更多
关键词 剩余寿命预测 河马优化算法 双向门控循环单元 健康曲线 滚动轴承
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基于一致性原理和ADMM的微电网群分层协调优化 认领 引用
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作者 王晓兰 管亚豪 宫玮丽 《兰州理工大学学报》 CAS 北大核心 2026年第3期72-80,共9页
针对微电网群中多个微电网之间的能量互济,以及解决微电网内部的风、光消纳和功率不平衡的问题,提出了一致性原理与交替方向乘子法(ADMM)结合对微电网群进行分层协调优化的方法.在微电网内部,考虑到风光发电及负荷的不确定性,采用高斯... 针对微电网群中多个微电网之间的能量互济,以及解决微电网内部的风、光消纳和功率不平衡的问题,提出了一致性原理与交替方向乘子法(ADMM)结合对微电网群进行分层协调优化的方法.在微电网内部,考虑到风光发电及负荷的不确定性,采用高斯回归对风、光及负荷进行预测,通过优化电网购电功率,柴油机发电和储能充放电功率,响应风光发电和负荷用电引起的功率波动.在微电网之间,通过一致性算法获取相邻微电网的期望交互功率信息并计算平均值,ADMM根据一致性算法提供的全局信息,对各微电网间的交互功率进行分布式优化,得到各微电网间交互功率的最优分配.通过算例分析得出,所提优化算法与传统ADMM相比,收敛速度更快.在实现微电网最低成本运行的同时,通过微电网间的功率交互,使微电网群的总运行成本最低. 展开更多
关键词 微电网群 交替方向乘子法 一致性算法 交互功率
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