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Support vector regression modeling in recursive just-in-time learning framework for adaptive soft sensing of naphtha boiling point in crude distillation unit 被引量:4
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作者 Venkata Vijayan S Hare Krishna Mohanta Ajaya Kumar Pani 《Petroleum Science》 SCIE CAS CSCD 2021年第4期1230-1239,共10页
Prediction of primary quality variables in real time with adaptation capability for varying process conditions is a critical task in process industries.This article focuses on the development of non-linear adaptive so... Prediction of primary quality variables in real time with adaptation capability for varying process conditions is a critical task in process industries.This article focuses on the development of non-linear adaptive soft sensors for prediction of naphtha initial boiling point(IBP)and end boiling point(EBP)in crude distillation unit.In this work,adaptive inferential sensors with linear and non-linear local models are reported based on recursive just in time learning(JITL)approach.The different types of local models designed are locally weighted regression(LWR),multiple linear regression(MLR),partial least squares regression(PLS)and support vector regression(SVR).In addition to model development,the effect of relevant dataset size on model prediction accuracy and model computation time is also investigated.Results show that the JITL model based on support vector regression with iterative single data algorithm optimization(ISDA)local model(JITL-SVR:ISDA)yielded best prediction accuracy in reasonable computation time. 展开更多
关键词 adaptive soft sensor Just in time learning Regression support vector regression Naphtha boiling point
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Fast Adaptive Support-Weight Stereo Matching Algorithm 被引量:2
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作者 Kai He Yunfeng Ge +1 位作者 Rui Zhen Jiaxing Yan 《Transactions of Tianjin University》 EI CAS 2017年第3期295-300,共6页
Adaptive support-weight (ASW) stereo matching algorithm is widely used in the field of three-dimensional (3D) reconstruction owing to its relatively high matching accuracy. However, since all the weight coefficients n... Adaptive support-weight (ASW) stereo matching algorithm is widely used in the field of three-dimensional (3D) reconstruction owing to its relatively high matching accuracy. However, since all the weight coefficients need to be calculated in the whole disparity range for each pixel, the algorithm is extremely time-consuming. To solve this problem, a fast ASW algorithm is proposed using twice aggregation. First, a novel weight coefficient which adapts cosine function to satisfy the weight distribution discipline is proposed to accomplish the first cost aggregation. Then, the disparity range is divided into several sub-ranges and local optimal disparities are selected from each of them. For each pixel, only the ASW at the location of local optimal disparities is calculated, and thus, the complexity of the algorithm is greatly reduced. Experimental results show that the proposed algorithm can reduce the amount of calculation by 70% and improve the matching accuracy by 6% for the 15 images on Middlebury Website on average. © 2017, Tianjin University and Springer-Verlag Berlin Heidelberg. 展开更多
关键词 Computational complexity Cosine transforms PIXELS
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Adaptive blind equalizer based on least square support vector machine
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作者 毛忠阳 王红星 +2 位作者 李军 赵志勇 宋恒 《Journal of Beijing Institute of Technology》 EI CAS 2011年第4期546-551,共6页
An adaptive blind support vector machine equalizer(ABSVME) is presented in this paper.The method is based upon least square support vector machine(LSSVM),and stems from signal feature reconstruction idea.By oversa... An adaptive blind support vector machine equalizer(ABSVME) is presented in this paper.The method is based upon least square support vector machine(LSSVM),and stems from signal feature reconstruction idea.By oversampling the output of a LSSVM equalizer and exploiting a reasonable decorrelation cost function design,the method achieves fine online channel tracing with Kumar express algorithm and static iterative learning algorithm incorporated.The method is verified through simulation and compared with other nonlinear equalizers.The results show that it provides excellent performance in nonlinear equalization and time-varying channel tracing.Although a constant module equalization algorithm requires that the signal has characteristic of constant module,this method has no such requirement. 展开更多
关键词 support vector machine(SVM) blind equalizer adaptive feature reconstruction
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Adaptive Nonlinear Model Predictive Control Using an On-line Support Vector Regression Updating Strategy
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作者 王平 杨朝合 +1 位作者 田学民 黄德先 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2014年第7期774-781,共8页
The performance of data-driven models relies heavily on the amount and quality of training samples, so it might deteriorate significantly in the regions where samples are scarce. The objective of this paper is to deve... The performance of data-driven models relies heavily on the amount and quality of training samples, so it might deteriorate significantly in the regions where samples are scarce. The objective of this paper is to develop an online SVR model updating strategy to track the change in the process characteristics efficiently with affordable computational burden. This is achieved by adding a new sample that violates the Karush–Kuhn–Tucker conditions of the existing SVR model and by deleting the old sample that has the maximum distance with respect to the newly added sample in feature space. The benefits offered by such an updating strategy are exploited to develop an adaptive model-based control scheme, where model updating and control task perform alternately.The effectiveness of the adaptive controller is demonstrated by simulation study on a continuous stirred tank reactor. The results reveal that the adaptive MPC scheme outperforms its non-adaptive counterpart for largemagnitude set point changes and variations in process parameters. 展开更多
关键词 adaptive control support vector regression Updating strategy Model predictive control
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Exploration on the Metadata Model of the SOA-based Adaptive Learning Support System
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作者 Tao LIU 《International Journal of Technology Management》 2014年第12期113-115,共3页
There are differences between the different individuals of learning. Adaptive learning support system is a learning system, which provides the learning supports suitable for the characteristics of the individuals acco... There are differences between the different individuals of learning. Adaptive learning support system is a learning system, which provides the learning supports suitable for the characteristics of the individuals according to the differences in the learning of individuals. In this paper, through the analysis on the adaptive learning support system, a system framework based on SOA is proposed and the research methods of the metadata model are emphatically discussed. 展开更多
关键词 adaptive Leaming support System METADATA SOA
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adaptive LASSO logistic回归模型应用于老年人养老意愿影响因素研究的探讨 被引量:23
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作者 韩耀风 覃文峰 +3 位作者 陈炜 李博涵 滕伯刚 方亚 《中国卫生统计》 CSCD 北大核心 2017年第1期18-22,共5页
目的探讨adaptive LASSO logistic回归模型在老年人养老意愿影响因素研究中的应用。方法基于厦门市60岁及以上老年人口的多阶段整群抽样调查数据,建立老年人养老意愿影响因素的adaptive LASSO logistic回归模型,通过交叉验证法选择模型... 目的探讨adaptive LASSO logistic回归模型在老年人养老意愿影响因素研究中的应用。方法基于厦门市60岁及以上老年人口的多阶段整群抽样调查数据,建立老年人养老意愿影响因素的adaptive LASSO logistic回归模型,通过交叉验证法选择模型中的调和参数λ;通过与全变量和逐步logistic回归结果的比较,探讨adaptive LASSO logistic回归模型的优势。结果共纳入1244名老年人,其养老意愿为家庭养老、社区居家养老和机构养老的比例分别为70.0%、21.1%和8.9%。交叉验证法选择的λ为0.018;此时adaptive LASSO logistic回归模型纳入的自变量为居住地、年龄、婚姻状况、文化程度、子女数、每月退休金收入、公费医疗和住院情况;BIC和AIC分别为1931、1888,均低于全变量logistic回归(2077、1923)和逐步logistic回归(2025、1912)。结论 adaptive LASSO logistic回归模型可用于老年人养老意愿影响因素研究。老年人的养老意愿受多个因素影响。 展开更多
关键词 adaptive LASSO LOGISTIC回归模型 养老模式 影响因素
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SVM-DT-Based Adaptive and Collaborative Intrusion Detection 被引量:13
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作者 Shaohua Teng Naiqi Wu +2 位作者 Haibin Zhu Luyao Teng Wei Zhang 《IEEE/CAA Journal of Automatica Sinica》 EI CSCD 2018年第1期108-118,共11页
As a primary defense technique, intrusion detection becomes more and more significant since the security of the networks is one of the most critical issues in the world. We present an adaptive collaboration intrusion ... As a primary defense technique, intrusion detection becomes more and more significant since the security of the networks is one of the most critical issues in the world. We present an adaptive collaboration intrusion detection method to improve the safety of a network. A self-adaptive and collaborative intrusion detection model is built by applying the Environmentsclasses, agents, roles, groups, and objects(E-CARGO) model. The objects, roles, agents, and groups are designed by using decision trees(DTs) and support vector machines(SVMs), and adaptive scheduling mechanisms are set up. The KDD CUP 1999 data set is used to verify the effectiveness of the method. The experimental results demonstrate the feasibility and efficiency of the proposed collaborative and adaptive intrusion detection method. Also, the proposed method is shown to be more predominant than the methods that use a set of single type support vector machine(SVM) in terms of detection precision rate and recall rate. 展开更多
关键词 adaptive and collaborative intrusion detection decision tree(DT) support vector machines(SVM)
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Robust adaptive UKF based on SVR for inertial based integrated navigation 被引量:7
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作者 Meng-de Zhang Hai-fa Dai +1 位作者 Bai-qing Hu Qi Chen 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2020年第4期846-855,共10页
Aiming at the problem that the traditional Unscented Kalman Filtering(UKF) algorithm can't solve the problem that the measurement covariance matrix is unknown and the measured value contains outliers,this paper pr... Aiming at the problem that the traditional Unscented Kalman Filtering(UKF) algorithm can't solve the problem that the measurement covariance matrix is unknown and the measured value contains outliers,this paper proposes a robust adaptive UKF algorithm based on Support Vector Regression(SVR).The algorithm combines the advantages of support vector regression with small samples,nonlinear learning ability and online estimation capability of adaptive algorithm based on innovation.Firstly,the SVR model is trained by using the innovation in the sliding window,and the new innovation is monitored.If the deviation between the estimated innovation and the measured innovation exceeds a given threshold,then measured innovation will be replaced by the predicted innovation,and then the processed innovation is used to calculate the measurement noise covariance matrix using the adaptive estimation algorithm.Simulation experiments and measured data experiments show that SVRUKF is significantly better than the traditional UKF,robust UKF and adaptive UKF algorithms for the case where the covariance matrix is unknown and the measured values have outliers. 展开更多
关键词 Integrated navigation support vector regression Unscented Kalman filter Robust filter adaptive filter
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Target Vehicle Selection Algorithm for Adaptive Cruise Control Based on Lane-changing Intention of Preceding Vehicle 被引量:4
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作者 Jun Yao Guoying Chen Zhenhai Gao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2021年第5期390-407,共18页
To improve the ride comfort and safety of a traditional adaptive cruise control(ACC)system when the preceding vehicle changes lanes,it proposes a target vehicle selection algorithm based on the prediction of the lane-... To improve the ride comfort and safety of a traditional adaptive cruise control(ACC)system when the preceding vehicle changes lanes,it proposes a target vehicle selection algorithm based on the prediction of the lane-changing intention for the preceding vehicle.First,the Next Generation Simulation dataset is used to train a lane-changing intention prediction algorithm based on a sliding window support vector machine,and the lane-changing intention of the preceding vehicle in the current lane is identified by lateral position offset.Second,according to the lane-changing intention and collision threat of the preceding vehicle,the target vehicle selection algorithm is studied under three different conditions:safe lane-changing,dangerous lane-changing,and lane-changing cancellation.Finally,the effectiveness of the proposed algorithm is verified in a co-simulation platform.The simulation results show that the target vehicle selection algorithm can ensure the smooth transfer of the target vehicle and effectively reduce the longitudinal acceleration fluctuation of the subject vehicle when the preceding vehicle changes lanes safely or cancels their lane change maneuver.In the case of a dangerous lane change,the target vehicle selection algorithm proposed in this paper can respond more rapidly to a dangerous lane change than the target vehicle selection method of the traditional ACC system;thus,it can effectively avoid collisions and improve the safety of the subject vehicle. 展开更多
关键词 Lane-changing intention Target vehicle selection support vector machine adaptive cruise control
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Credit risk evaluation using adaptive Lq penalty SVM with Gauss kernel 被引量:1
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作者 Sun, Dongxia Li, Jianping Wei, Liwei 《Journal of Southeast University(English Edition)》 EI CAS 2008年第S1期33-36,共4页
In order to improve the performance of support vector machine (SVM) applications in the field of credit risk evaluation, an adaptive Lq SVM model with Gauss kernel (ALqG-SVM) is proposed to evaluate credit risks. The ... In order to improve the performance of support vector machine (SVM) applications in the field of credit risk evaluation, an adaptive Lq SVM model with Gauss kernel (ALqG-SVM) is proposed to evaluate credit risks. The non-adaptive penalty of the object function is extended to (0, 2] to increase classification accuracy. To further improve the generalization performance of the proposed model, the Gauss kernel is introduced, thus the non-linear classification problem can be linearly separated in higher dimensional feature space. Two UCI credit datasets and a real life credit dataset from a US major commercial bank are used to check the efficiency of this model. Compared with other popular methods, satisfactory results are obtained through a novel method in the area of credit risk evaluation. So the new model is an excellent choice. 展开更多
关键词 credit risk evaluation adaptive penalty classification support vector machine feature selection
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Defocus Blur Segmentation Using Local Binary Patterns with Adaptive Threshold 被引量:1
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作者 Usman Ali Muhammad Tariq Mahmood 《Computers, Materials & Continua》 SCIE EI 2022年第4期1597-1611,共15页
Enormousmethods have been proposed for the detection and segmentation of blur and non-blur regions of the images.Due to the limited available information about blur type,scenario and the level of blurriness,detection ... Enormousmethods have been proposed for the detection and segmentation of blur and non-blur regions of the images.Due to the limited available information about blur type,scenario and the level of blurriness,detection and segmentation is a challenging task.Hence,the performance of the blur measure operator is an essential factor and needs improvement to attain perfection.In this paper,we propose an effective blur measure based on local binary pattern(LBP)with adaptive threshold for blur detection.The sharpness metric developed based on LBP used a fixed threshold irrespective of the type and level of blur,that may not be suitable for images with variations in imaging conditions,blur amount and type.Contrarily,the proposed measure uses an adaptive threshold for each input image based on the image and blur properties to generate improved sharpness metric.The adaptive threshold is computed based on the model learned through support vector machine(SVM).The performance of the proposed method is evaluated using two different datasets and is compared with five state-of-the-art methods.Comparative analysis reveals that the proposed method performs significantly better qualitatively and quantitatively against all of the compared methods. 展开更多
关键词 adaptive threshold blur measure defocus blur segmentation local binary pattern support vector machine
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Soft measurement for component content based on adaptive model of Pr/Nd color features 被引量:5
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作者 陆荣秀 杨辉 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第12期1981-1986,共6页
For measurement of component content in the extraction and separation process of praseodymium/neodymium(Pr/Nd), a soft measurement method was proposed based on modeling of ion color features, which is suitable for fas... For measurement of component content in the extraction and separation process of praseodymium/neodymium(Pr/Nd), a soft measurement method was proposed based on modeling of ion color features, which is suitable for fast estimation of component content in production field. Feature analysis on images of the solution is conducted,which are captured from Pr/Nd extraction/separation field. H/S components in the HSI color space are selected as model inputs, so as to establish the least squares support vector machine(LSSVM) model for Nd(Pr) content,while the model parameters are determined with the GA algorithm. To improve the adaptability of the model,the adaptive iteration algorithm is used to correct parameters of the LSSVM model, on the basis of model correction strategy and new sample data. Using the field data collected from rare earth extraction production, predictive methods for component content and comparisons are given. The results indicate that the proposed method presents good adaptability and high prediction precision, so it is applicable to the fast detection of element content in the rare earth extraction. 展开更多
关键词 Pr/Nd extraction Color feature Component content adaptive iterative least squares support vector machine Real-time correction
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A novel adaptive classification scheme for digital modulations in satellite communication 被引量:1
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作者 吴丹 Gu Xuemai Guo Qing 《High Technology Letters》 EI CAS 2007年第2期145-149,共5页
To make the modulation classification system more suitable for signals in a wide range of signal to noise ratios (SNRs), a novel adaptive modulation classification scheme is presented in this paper. Differ-ent from ... To make the modulation classification system more suitable for signals in a wide range of signal to noise ratios (SNRs), a novel adaptive modulation classification scheme is presented in this paper. Differ-ent from traditional schemes, the proposed scheme employs a new SNR estimation algorithm for small samples before modulation classification, which makes the modulation classifier work adaptively according to estimated SNRs. Furthermore, it uses three efficient features and support vector machines (SVM) in modulation classification. Computer simulation shows that the scheme can adaptively classify ten digital modulation types (i.e. 2ASK, 4ASK, 2FSK, 4FSK, 2PSK, 4PSK, 16QAM, TFM, π/4QPSK and OQPSK) at SNRS ranging from 0dB to 25dB and success rates are over 95% when SNR is not lower than 3dB. Accuracy, efficiency and simplicity of the proposed scheme are obviously improved, which make it more adaptive to engineering applications. 展开更多
关键词 adaptive modulation classification support vector machine SNR estimation digital modulation
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Adaptive Signal Conditioning Technology in Fighter Weapon System Test
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作者 范惠林 侯满义 +1 位作者 耿振野 徐洪吉 《Defence Technology(防务技术)》 SCIE EI CAS 2009年第4期317-320,共4页
In order to realize the real-time and precise test for a weapon system of a certain type of fighter,a signal classification method according to attributes is proposed,common input channels for multiple signals are con... In order to realize the real-time and precise test for a weapon system of a certain type of fighter,a signal classification method according to attributes is proposed,common input channels for multiple signals are configured optimally,and a test adapter and an adaptive signal conditioning module is designed. The hardware of conditioning module can be configured flexibly and the programmable test range can be adjusted owing to programmable multiplexer. An FPGA adaptive filter is designed by the calculated filter coefficient vectors with LMS method to solve the problem of parallel test of fighter weapon system in electromagnetic interference environment. The adaptive signal conditioning technology is characterized by high efficiency,precision and integration. Its application makes the test system successful to conduct real-time and parallel test for a weapon system,which is developed based on VXI bus and virtual-instrument technology. 展开更多
关键词 ground-based facility and technical support of aviation fighter weapon system test signal conditioning adaptive FILTER
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FUZZY ADAPTIVE CONTROL MODEL FOR PROCESS IN NICKEL MATTE SMELTING FURNACE 被引量:1
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作者 Mei, Chi Peng, Xiaoqi Zhou, Jiemin 《中国有色金属学会会刊:英文版》 EI CSCD 1994年第3期9-11,共3页
FUZZYADAPTIVECONTROLMODELFORPROCESSINNICKELMATTESMELTINGFURNACEMei,ChiPeng,XiaoqiZhou,Jiemin(DepartmentofApp... FUZZYADAPTIVECONTROLMODELFORPROCESSINNICKELMATTESMELTINGFURNACEMei,ChiPeng,XiaoqiZhou,Jiemin(DepartmentofAppliedPhysicsandHea... 展开更多
关键词 NICKEL MATTE SMELTING FURNACE FUZZY CONTROL
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基于数字孪生和深度强化学习的矿井超前液压支架自适应抗冲支护方法 被引量:1
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作者 张帆 邵光耀 +1 位作者 李昱翰 李玉雪 《工矿自动化》 CSCD 北大核心 2024年第6期23-29,45,共8页
受深部开采冲击地压等地质灾害扰动的影响,存在矿井超前支护系统自感知能力差、智能抗冲自适应能力弱、缺乏决策控制能力等问题。针对上述问题,提出了一种基于数字孪生和深度强化学习的矿井超前液压支架自适应抗冲支护方法。通过多源传... 受深部开采冲击地压等地质灾害扰动的影响,存在矿井超前支护系统自感知能力差、智能抗冲自适应能力弱、缺乏决策控制能力等问题。针对上述问题,提出了一种基于数字孪生和深度强化学习的矿井超前液压支架自适应抗冲支护方法。通过多源传感器感知巷道环境和超前液压支架支护状态,在虚拟世界中创建物理实体的数字孪生模型,其中物理模型精确展现超前液压支架的结构特征和细节,控制模型实现超前液压支架的自适应控制,机理模型实现对超前液压支架自适应支护的逻辑描述和机理解释,数据模型存储超前液压支架实体运行数据和孪生数据,仿真模型完成超前液压支架立柱仿真以实现超前液压支架与数字孪生模型虚实交互。根据基于深度Q网络(DQN)的超前液压支架自适应抗冲决策算法,对仿真环境中巷道抗冲支护进行智能决策,并依据决策结果对物理实体和数字孪生模型下达调控指令,实现超前液压支架智能控制。实验结果表明:立柱位移与压力变化一致,说明超前液压支架立柱仿真模型设计合理,从而验证了数字孪生模型的准确性;基于DQN的矿井超前液压支架自适应抗冲决策算法可通过调节液压支架控制器PID参数,自适应调控立柱压力,提升巷道安全等级,实现超前液压支架自适应抗冲支护。 展开更多
关键词 矿井智能抗冲 超前液压支架 自适应支护 数字孪生 深度强化学习 深度Q网络 DQN
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基于参数自适应SVR和VMD-TCN的水电机组劣化趋势预测 被引量:2
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作者 王淑青 柯洋洋 +2 位作者 胡文庆 罗平章 李青珏 《中国农村水利水电》 北大核心 2024年第4期193-198,204,共7页
针对水电机组难以利用实时监测数据对机组劣化状态进行有效评估,以及水电机组不同运行工况对运行状态指标趋势预测模型参数影响显著的问题,提出一种基于参数自适应支持向量回归机(SVR)、变分模态分解(VMD)和时间卷积网络(TCN)的水电机... 针对水电机组难以利用实时监测数据对机组劣化状态进行有效评估,以及水电机组不同运行工况对运行状态指标趋势预测模型参数影响显著的问题,提出一种基于参数自适应支持向量回归机(SVR)、变分模态分解(VMD)和时间卷积网络(TCN)的水电机组劣化趋势预测方法;首先按照功率和水头将机组运行工况细化为若干典型工况,在此基础上采用改进天鹰算法建立SVR模型,对各个工况下的预测参数进行寻优,建立起工况与最优参数的数据;再通过神经网络对工况和最优预测参数进行拟合,构建出映射两者复杂关系的非线性函数,然后将构建出的映射关系加入到传统的SVR中,实现适应于水电机组工况变化的自适应SVR健康模型;其次,根据健康模型输出的标准值和监测数据,计算出劣化趋势序列;最后,考虑到劣化趋势序列的非线性因素,建立了一个基于VMD-TCN的时间序列预测模型,以实现对劣化趋势的准确预测。并设计多组对比实验,验证所提出模型的精度更高,时间更快。 展开更多
关键词 水电机组 劣化趋势预测 参数自适应 支持向量回归机 变分模态分解 时间卷积网络
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改进黑猩猩算法的光伏发电功率短期预测 被引量:3
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作者 谢国民 陈天香 《电力系统及其自动化学报》 CSCD 北大核心 2024年第2期135-143,共9页
针对晴空、非晴空条件下光伏出力预测精度不高等问题,提出一种改进K均值(K-means++)算法和黑猩猩优化算法CHOA(chimpanzee optimization algorithm)相结合,优化最小二乘支持向量机LSSVM(least squares support vector machine)的模型,... 针对晴空、非晴空条件下光伏出力预测精度不高等问题,提出一种改进K均值(K-means++)算法和黑猩猩优化算法CHOA(chimpanzee optimization algorithm)相结合,优化最小二乘支持向量机LSSVM(least squares support vector machine)的模型,进行光伏功率预测。首先,利用密度聚类和混合评价函数改进K-means++对原始数据进行自适应类别划分。其次,通过相关性分析和随机森林特征提取构建模型的输入特征集。最后,根据特征集建立基于DK-PCHOA-LSSVM的短期光伏发电预测模型。结合实际算例,结果表明:该模型在恶劣天气下预测精度明显优于其他模型,验证了其有效性和优越性。 展开更多
关键词 光伏功率短期预测 自适应聚类 最小二乘支持向量机 黑猩猩优化算法 极端天气
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社会情感能力对大学生社会适应能力的影响:领悟社会支持与积极应对的链式中介 被引量:1
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作者 唐红娟 张丽楠 《牡丹江师范学院学报(社会科学版)》 2024年第1期52-58,共7页
为了探讨大学生社会情感能力对社会适应能力的影响及领悟社会支持和积极应对在两者之间的链式中介作用,采用大学生社会情感能力量表、领悟社会支持量表、积极应对方式量表和社会适应能力诊断量表对374名大学生进行问卷调查。结果发现:(1... 为了探讨大学生社会情感能力对社会适应能力的影响及领悟社会支持和积极应对在两者之间的链式中介作用,采用大学生社会情感能力量表、领悟社会支持量表、积极应对方式量表和社会适应能力诊断量表对374名大学生进行问卷调查。结果发现:(1)大学生的社会情感能力、社会适应能力、领悟社会支持和积极应对方式均两两显著正相关;(2)大学生社会情感能力显著正向影响社会适应能力;(3)领悟社会支持和积极应对在大学生社会情感能力与社会适应能力之间均起部分中介作用;(4)领悟社会支持和积极应对在大学生社会情感能力与社会适应的关系中构成链式中介。研究扩充了社会情感能力影响学生社会适应能力的研究机制,同时为提升大学生的社会适应能力提供启示。 展开更多
关键词 社会情感能力 社会适应能力 领悟社会支持 积极应对 大学生
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基于表面辐射声信号的柴油机进气及齿轮故障诊断
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作者 李斌 林杰威 +3 位作者 朱小龙 林耕毅 张益铭 张俊红 《排灌机械工程学报》 CSCD 北大核心 2024年第8期843-850,共8页
利用声振信号进行发动机故障诊断过程中,部分故障激励仅在发动机表面特定位置的振动中有较强响应,振动测点要求高,需要接触测量,部分场景难以实现.为此,提出了一种以表面辐射声为媒介、以自适应变分模态提取(adaptive variational mode ... 利用声振信号进行发动机故障诊断过程中,部分故障激励仅在发动机表面特定位置的振动中有较强响应,振动测点要求高,需要接触测量,部分场景难以实现.为此,提出了一种以表面辐射声为媒介、以自适应变分模态提取(adaptive variational mode extraction,AVME)进行预处理的柴油机进气故障和齿轮故障诊断方法.开展了某直列六缸重型柴油机的进气滤清器堵塞、气门间隙异常和正时齿轮损伤3类故障状态的台架试验,获取了不同故障程度下发动机表面辐射噪声.基于改进的AVME方法,实现噪声信号本征模函数(intrinsic mode function,IMF)的最优分解,通过计算IMF与原信号间的互相关系数,提取高相关IMF构成故障诊断输入.经预处理后,声信号故障特征得到有效增强,再输入到麻雀搜索算法优化支持向量机模型(support vector machine model optimized by sparrow search algorithm,SSA-SVM),进行特征参量和模型参数协同优化可以获得更好的诊断精度.试验验证表明,无需在半消声室测试,仅使用单通道声信号对3类11种程度的进气系统和齿轮故障进行诊断,前端噪声准确率最高(98.89%),顶部噪声准确率最低(88.78%);使用前、顶、后三通道噪声数据后,诊断精度可提升至99.57%.研究结论为基于声信号等非接触测量的发动机故障诊断提供了参考. 展开更多
关键词 柴油机 声信号 故障诊断 自适应变分模态提取 支持向量机
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