期刊文献+
共找到110篇文章
< 1 2 6 >
每页显示 20 50 100
SNP site-drug association prediction algorithm based on denoising variational auto-encoder 被引量:2
1
作者 SONG Xiaoyu FENG Xiaobei +3 位作者 ZHU Lin LIU Tong WU Hongyang LI Yifan 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2022年第3期300-308,共9页
Single nucletide polymorphism(SNP)is an important factor for the study of genetic variation in human families and animal and plant strains.Therefore,it is widely used in the study of population genetics and disease re... Single nucletide polymorphism(SNP)is an important factor for the study of genetic variation in human families and animal and plant strains.Therefore,it is widely used in the study of population genetics and disease related gene.In pharmacogenomics research,identifying the association between SNP site and drug is the key to clinical precision medication,therefore,a predictive model of SNP site and drug association based on denoising variational auto-encoder(DVAE-SVM)is proposed.Firstly,k-mer algorithm is used to construct the initial SNP site feature vector,meanwhile,MACCS molecular fingerprint is introduced to generate the feature vector of the drug module.Then,we use the DVAE to extract the effective features of the initial feature vector of the SNP site.Finally,the effective feature vector of the SNP site and the feature vector of the drug module are fused input to the support vector machines(SVM)to predict the relationship of SNP site and drug module.The results of five-fold cross-validation experiments indicate that the proposed algorithm performs better than random forest(RF)and logistic regression(LR)classification.Further experiments show that compared with the feature extraction algorithms of principal component analysis(PCA),denoising auto-encoder(DAE)and variational auto-encode(VAE),the proposed algorithm has better prediction results. 展开更多
关键词 association prediction k-mer molecular fingerprinting support vector machine(SVM) denoising variational auto-encoder(DVAE)
在线阅读 下载PDF
Constrained Hamilton variational principle for shallow water problems and Zu-class symplectic algorithm 被引量:2
2
作者 Feng WU Wanxie ZHONG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2016年第1期1-14,共14页
In this paper, the shallow water problem is discussed. By treating the incompressible condition as the constraint, a constrained Hamilton variational principle is presented for the shallow water problem. Based on the ... In this paper, the shallow water problem is discussed. By treating the incompressible condition as the constraint, a constrained Hamilton variational principle is presented for the shallow water problem. Based on the constrained Hamilton variational principle, a shallow water equation based on displacement and pressure (SWE-DP) is developed. A hybrid numerical method combining the finite element method for spa- tial discretization and the Zu-class method for time integration is created for the SWE- DP. The correctness of the proposed SWE-DP is verified by numerical comparisons with two existing shallow water equations (SWEs). The effectiveness of the hybrid numerical method proposed for the SWE-DP is also verified by numerical experiments. Moreover, the numerical experiments demonstrate that the Zu-class method shows excellent perfor- mance with respect to simulating the long time evolution of the shallow water. 展开更多
关键词 shallow water equation (SWE) constrained Hamilton variational principle Zu-class method
在线阅读 下载PDF
BLOW-UP OF A CLASS OF SEMILINEAR PARABOLIC VARIATIONAL INEQUALITIES
3
作者 吴新民 韦志辉 《四川师范大学学报(自然科学版)》 CAS CSCD 1991年第1期69-70,共2页
In this paper we study the blow-up behavior for a class of semilinear parabolic variational inequalities;whereK = {u ∈L<sup>2</sup>(0,T;H<sub>0</sub><sup>1</sup>(Ω))|u(x,t)... In this paper we study the blow-up behavior for a class of semilinear parabolic variational inequalities;whereK = {u ∈L<sup>2</sup>(0,T;H<sub>0</sub><sup>1</sup>(Ω))|u(x,t)≥ψ(x) a. e. (x,t) ∈Ω×(0,T), u(x,0) = (x)},andis a uniformly elliptic operator.We prove the following main theorem.Theorem Let u(x,t) be a local solution of problem (I),u∈C(0,T;H<sup>2</sup>(Ω)∩H<sub>0</sub><sup>1</sup>(Q)),u<sub>i</sub>∈L<sup>2</sup>(0,T;L<sup>2</sup>(Ω)), and following conditions are satisfied.(1) There exists a continuously differentiable function G(x,s) and a positive number α,such 展开更多
关键词 SEMILINEAR ELLIPTIC parabolic DIFFERENTIABLE variational class satisfied UNIFORMLY continuously 阴石
在线阅读 下载PDF
Feature-aided pose estimation approach based on variational auto-encoder structure for spacecrafts
4
作者 Yanfang LIU Rui ZHOU +2 位作者 Desong DU Shuqing CAO Naiming QI 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2024年第8期329-341,共13页
Real-time 6 Degree-of-Freedom(DoF)pose estimation is of paramount importance for various on-orbit tasks.Benefiting from the development of deep learning,Convolutional Neural Networks(CNNs)in feature extraction has yie... Real-time 6 Degree-of-Freedom(DoF)pose estimation is of paramount importance for various on-orbit tasks.Benefiting from the development of deep learning,Convolutional Neural Networks(CNNs)in feature extraction has yielded impressive achievements for spacecraft pose estimation.To improve the robustness and interpretability of CNNs,this paper proposes a Pose Estimation approach based on Variational Auto-Encoder structure(PE-VAE)and a Feature-Aided pose estimation approach based on Variational Auto-Encoder structure(FA-VAE),which aim to accurately estimate the 6 DoF pose of a target spacecraft.Both methods treat the pose vector as latent variables,employing an encoder-decoder network with a Variational Auto-Encoder(VAE)structure.To enhance the precision of pose estimation,PE-VAE uses the VAE structure to introduce reconstruction mechanism with the whole image.Furthermore,FA-VAE enforces feature shape constraints by exclusively reconstructing the segment of the target spacecraft with the desired shape.Comparative evaluation against leading methods on public datasets reveals similar accuracy with a threefold improvement in processing speed,showcasing the significant contribution of VAE structures to accuracy enhancement,and the additional benefit of incorporating global shape prior features. 展开更多
关键词 Pose estimation variational auto-encoder Feature-aided Pose Estimation Approach On-orbit measurement tasks Simulated and experimental dataset
原文传递
ON A CLASS OF QUASI VARIATIONAL INEQUALITIES
5
作者 M.A.Noor 《Analysis in Theory and Applications》 1996年第3期18-28,共11页
In this paper,we introduce and study a new class of quasi variational inequalities.Using'essentially the projection technique and its variant forms,we establish the equivalence between generalized nonlinear quasi ... In this paper,we introduce and study a new class of quasi variational inequalities.Using'essentially the projection technique and its variant forms,we establish the equivalence between generalized nonlinear quasi variational inequalities and the fixed point problems.This equivalence is then used to suggest and analyze a number of new iterative algorithms.These new results include the corresponding known results for generalized quasi variational inequalities as special cases. 展开更多
关键词 HOPF ON A class OF QUASI variational INEQUALITIES
在线阅读 下载PDF
A CLASS OF VARIATIONAL DIFFERENCE SCHEMES FOR A SINGULAR PERTURBATION PROBLEM
6
作者 林平 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1989年第4期353-359,共7页
In this paper, a singularly perturbed boundary value problem for second order self-adjoint ordinary differential equation is discussed. A class of variational difference schemes is constructed by the finite element me... In this paper, a singularly perturbed boundary value problem for second order self-adjoint ordinary differential equation is discussed. A class of variational difference schemes is constructed by the finite element method. Uniform convergence about small parameter is proved under a weaker smooth condition with respect to the coefficients of the equation. The schemes studied in refs. [1], [3], [4] and [51 belong to the cllass. 展开更多
关键词 A class OF variational DIFFERENCE SCHEMES FOR A SINGULAR PERTURBATION PROBLEM
在线阅读 下载PDF
ON ITERATIVE ALGORITHMS FOR A CLASS OF NONLINEAR VARIATIONAL INEQUALITIES
7
作者 M. A. Moor 《Analysis in Theory and Applications》 1995年第3期95-105,共11页
In this paper we use the auxiliary principle technique to suggest and analyze novel and innovative iterative algorithms for a class of nonlinear variational inequalities. Several special cases, which can be obtained f... In this paper we use the auxiliary principle technique to suggest and analyze novel and innovative iterative algorithms for a class of nonlinear variational inequalities. Several special cases, which can be obtained from our main results, are also discussed. 展开更多
关键词 ON ITERATIVE ALGORITHMS FOR A class OF NONLINEAR variational INEQUALITIES
在线阅读 下载PDF
Variational Approach for the Adapted Solution of Backw ard Stochastic Differential Equations with Locally Lipschitz Diffusion Coefficients 被引量:1
8
作者 谢臻赟 刘奕 《Journal of Donghua University(English Edition)》 EI CAS 2012年第4期341-350,共10页
One existence integral condition was obtained for the adapted solution of the general backward stochastic differential equations(BSDEs). Then by solving the integral constraint condition, and using a limit procedure, ... One existence integral condition was obtained for the adapted solution of the general backward stochastic differential equations(BSDEs). Then by solving the integral constraint condition, and using a limit procedure, a new approach method is proposed and the existence of the solution was proved for the BSDEs if the diffusion coefficients satisfy the locally Lipschitz condition. In the special case the solution was a Brownian bridge. The uniqueness is also considered in the meaning of "F0-integrable equivalent class" . The new approach method would give us an efficient way to control the main object instead of the "noise". 展开更多
关键词 backward stochastic differential equation (BSDE) variational approach locally Lipschitz condition EXISTENCE Fointegrable equivalent class UNIQUENESS Brownian bridge
在线阅读 下载PDF
Statistical Study of foF2 Diurnal Variation at Dakar Station from 1971 to 1996:Effect of Geomagnetic Classes of Activity on Seasonal Variation at Solar Minimum and Maximum
9
作者 Ali Mahamat Nour Ouattara Frederic +3 位作者 Zerbo Jean Louis Gyebre Aristide Marie Frederic Nanema Emmanuel Zougmore Francois 《International Journal of Geosciences》 2015年第3期201-208,共8页
The statistical study of F2 layer critical frequency at Dakar station from 1971 to 1996 is carried out. This paper shows foF2 statistical diurnal for all geomagnetic activities and all seasons and that during solar ma... The statistical study of F2 layer critical frequency at Dakar station from 1971 to 1996 is carried out. This paper shows foF2 statistical diurnal for all geomagnetic activities and all seasons and that during solar maximum and minimum phases. It emerges that foF2 diurnal variation graphs at Dakar station exhibits the different types of foF2 profiles in African EIA regions. The type of profile depends on solar activity, season and solar phase. During solar minimum and under quiet time condition, data show?the signature of a strength electrojet that is coupled with intense counter electrojet in the afternoon. Under disturbed conditions,?mean intense electrojet is observed in winter?during fluctuating and recurrent activities. Intense counter electrojet is seen under fluctuating and shock activities in all seasons coupled with strength electrojet in autumn. In summer?and spring under all geomagnetic activity condition, there is intense counter electrojet. During solar maximum, in summer and spring there is no electrojet under geomagnetic activity conditions.?Winter shows a mean intense electrojet. Winter and autumn are marked by the signature of the reversal electric field. 展开更多
关键词 foF2 Diurnal variation Solar Cycle Phases Geomagnetic Activity classes Seasonal Effects E Region Electric Currents
在线阅读 下载PDF
Oversampling for class-imbalanced learning in credit risk assessment based on CVAE-WGAN-gp model
10
作者 Kaiming Wang Qing Yang 《中国科学技术大学学报》 北大核心 2025年第7期37-48,36,I0001,I0002,共15页
Credit risk assessment is a crucial task in bank risk management.By making lending decisions based on credit risk assessment results,banks can reduce the probability of non-performing loans.However,class imbalance in ... Credit risk assessment is a crucial task in bank risk management.By making lending decisions based on credit risk assessment results,banks can reduce the probability of non-performing loans.However,class imbalance in bank credit default datasets limits the predictive performance of traditional machine learning and deep learning models.To address this issue,this study employs the conditional variational autoencoder-Wasserstein generative adversarial network with gradient penalty(CVAE-WGAN-gp)model for oversampling,generating samples similar to the original default customer data to enhance model prediction performance.To evaluate the quality of the data generated by the CVAE-WGAN-gp model,we selected several bank loan datasets for experimentation.The experimental results demonstrate that using the CVAE-WGAN-gp model for oversampling can significantly improve the predictive performance in credit risk assessment problems. 展开更多
关键词 credit risk assessment class imbalance OVERSAMPLING conditional variational autoencoder(CVAE) generative adversarial network(GAN)
在线阅读 下载PDF
基于注意力和变分类自编码的PCB小样本缺陷检测
11
作者 宋涛 冉璐 +4 位作者 杨金河 邢镔 龙邹荣 王泓俊 李梓谦 《计算机工程与应用》 北大核心 2026年第4期363-372,共10页
针对小样本印刷电路板(printed circuit board,PCB)缺陷样本少、样本失衡、难泛化导致检测精度较低的问题,引入元学习方案,在元学习目标检测框架上提出基于注意力和变分类自编码的小样本缺陷检测方法。针对支持分支建模易受噪声影响问题... 针对小样本印刷电路板(printed circuit board,PCB)缺陷样本少、样本失衡、难泛化导致检测精度较低的问题,引入元学习方案,在元学习目标检测框架上提出基于注意力和变分类自编码的小样本缺陷检测方法。针对支持分支建模易受噪声影响问题,提出基于注意力的背景弱化模块,通过对注意力机制进行改进,使模型能够自适应改变重要性,聚焦前景信息与周围差异,减少背景干扰。鉴于支持分支缺乏类特征提取,导致查询特征与支持特征聚合后容易发生漏检、错检的问题,提出变分类自编码模块,利用概率分布以及重参数化获得类特征,提高新类检测准确率。为了充分探索查询特征与支持特征高级特征关系,提出多特征聚合模块,利用元素乘法、减法运算对两种特征之间的相似点和差异性进行建模,同时通过查询原型减少随机采样带来的噪声。实验结果表明,在PKU-Market-PCB数据集上,该方法在10样本下新类、基类准确率最高可达到65.3%、89.7%。 展开更多
关键词 小样本目标检测 元学习 注意力机制 变分类自编码 多特征聚合
在线阅读 下载PDF
Genetic Variation and Differentiation of Larix decidua Populations in Swiss Alps
12
作者 赵桂仿 Fran0is FELBER Philippe KPFER 《Acta Botanica Sinica》 CSCD 2001年第7期731-735,共5页
Genetic diversity within and among six subpopulations of Larix decidua Mill. from two altitudinal transects of Swiss Alps was investigated using 6 enzyme systems coding for 8 loci. Globally, the mean proportion of pol... Genetic diversity within and among six subpopulations of Larix decidua Mill. from two altitudinal transects of Swiss Alps was investigated using 6 enzyme systems coding for 8 loci. Globally, the mean proportion of polymorphic loci was 22.9%, the average number of alleles per locus was 1.3, and the mean expected heterozygosity was 0.095. Only 5.8% of the genetic variation resided among populations. The mean genetic distance was 0.006. Several significant differences of gene frequencies were found between different age classes. Positive values of the species mean fixation index observed in this study suggested a considerable deficit of heterozygotes in the populations of L. decidua of Swiss Alps. At one of the sites (Arpette), the highest subpopulation in elevation gave the lowest level of genetic diversity (as evidenced by the lowest proportion of polymorphic loci and the lowest mean expected heterozygosity) and the largest value of genetic distance when compared to other subpopulations. The genetic differences between the highest subpopulation and the other ones suggest that the founder effect may be an important factor influencing genetic differentiation of L. decidua populations at Arpette transect. 展开更多
关键词 Larix decidua Swiss Alps allozyme variation genetic differentiation age classes
在线阅读 下载PDF
On the Social Variation of English Language
13
作者 张知国 《海外英语》 2012年第13期265-266,共2页
This paper concentrates on social variation to explain how it works in English language and attempt to introduce it to the advanced Chinese learners.
关键词 SOCIAL variatION SOCIAL DIALECT SOCIAL class gende
在线阅读 下载PDF
Low Frequency Residential Load Disaggregation via Improved Variational Auto-encoder and Siamese Network
14
作者 Cheng Qian Zaijun Wu +2 位作者 Dongliang Xu Qinran Hu Yu Liu 《CSEE Journal of Power and Energy Systems》 2025年第5期2137-2149,共13页
Non-intrusive load monitoring(NILM)can infer load profiles for each individual appliance from aggregated power consumption signals without installing extra sub-meters.However,performance of traditional energy disaggre... Non-intrusive load monitoring(NILM)can infer load profiles for each individual appliance from aggregated power consumption signals without installing extra sub-meters.However,performance of traditional energy disaggregation methods deteriorates in complex environments,especially susceptible to the presence of other high power consumption appliances.Practicalities are also limited by diversity of household load patterns and measurement errors.In order to address these problems,a hybrid deep learning model consisting of two steps is proposed in this paper.First,an improved variational autoencoder(VAE)structure is introduced for preliminary energy disaggregation,where the encoder and decoder layers are long short-term networks(LSTM)to extract temporal characteristics of active power signals.Afterward,a post-processing method based on Siamese one-dimensional convolutional neural network(S-1D-CNN)is adopted to remove incorrectly predicted activation segments of target appliances.Experiments are conducted on two public datasets,and results show remarkable improvements on prediction accuracy over other deep learning methods.Both transferability and stability of the proposed model are verified under different working conditions. 展开更多
关键词 Deep learning NILM POST-PROCESSING Siamese network variational auto-encoder
原文传递
VMGP:A unified variational auto-encoder based multi-task model for multi-phenotype,multi-environment,and cross-population genomic selection in plants
15
作者 Xiangyu Zhao Fuzhen Sun +6 位作者 Jinlong Li Dongfeng Zhang Qiusi Zhang Zhongqiang Liu Changwei Tan Hongxiang Ma Kaiyi Wang 《Artificial Intelligence in Agriculture》 2025年第4期829-842,共14页
Plant breeding stands as a cornerstone for agricultural productivity and the safeguarding of food security.The advent of Genomic Selection heralds a new epoch in breeding,characterized by its capacity to harness whole... Plant breeding stands as a cornerstone for agricultural productivity and the safeguarding of food security.The advent of Genomic Selection heralds a new epoch in breeding,characterized by its capacity to harness whole-genome variation for genomic prediction.This approach transcends the need for prior knowledge of genes associated with specific traits.Nonetheless,the vast dimensionality of genomic data juxtaposed with the relatively limited number of phenotypic samples often leads to the“curse of dimensionality”,where traditional statistical,machine learning,and deep learning methods are prone to overfitting and suboptimal predictive performance.To surmount this challenge,we introduce a unified Variational auto-encoder based Multi-task Genomic Prediction model(VMGP)that integrates self-supervised genomic compression and reconstruction with multiple prediction tasks.This approach provides a robust solution,offering a formidable predictive framework that has been rigorously validated across public datasets for wheat,rice,and maize.Our model demonstrates exceptional capabilities in multi-phenotype and multi-environment genomic prediction,successfully navigating the complexities of cross-population genomic selection and underscoring its unique strengths and utility.Furthermore,by integrating VMGP with model interpretability,we can effectively triage relevant single nucleotide polymorphisms,thereby enhancing prediction performance and proposing potential cost-effective genotyping solutions.The VMGP framework,with its simplicity,stable predictive prowess,and open-source code,is exceptionally well-suited for broad dissemination within plant breeding programs.It is particularly advantageous for breeders who prioritize phenotype prediction yet may not possess extensive knowledge in deep learning or proficiency in parameter tuning. 展开更多
关键词 Genomic selection variational auto-encoder MULTI-TASK Deep learning Genomic prediction
原文传递
Study of current distribution generation in PEMFC based on conditional variational auto-encoder
16
作者 Chengyin Shi Cong Yin +2 位作者 Weilong Luo Hailong Liu Hao Tang 《Energy and AI》 2025年第3期578-591,共14页
The Proton Exchange Membrane Fuel Cell(PEMFC)converts the chemical energy of hydrogen fuel directly into electrical energy with broad application prospects.Understanding how current density is distributed in the PEMFC... The Proton Exchange Membrane Fuel Cell(PEMFC)converts the chemical energy of hydrogen fuel directly into electrical energy with broad application prospects.Understanding how current density is distributed in the PEMFC systems is crucial as it is a key factor influencing system performance.However,direct modeling for current distribution may encounter the challenge of dimensional catastrophe owing to the high dimensionality of the data.This paper uses a high-resolution segmented measurement device with 396 points to conduct experimental tests on the current distribution of a PEMFC with reactive area of 406 cm^(2) during a stepwise increase in load current.The current distribution is modeled based on the test results to learn the mapping relationship between the experimental parameters and the current distribution.The proposed model utilizes a Conditional Variational Auto-Encoder(CVAE)to generate current distributions.The MSE(Mean-Square Error)of the trained CVAE model reaches 9.2×10^(-5),and the comparison results show that the 222.9A current distribution error has the largest MSE of 6.36×10^(-4) and a KL Divergence(Kullback-Leibler Divergence)of 9.55×10^(-4),both of which are at a low level.This model enables the direct determination of the current distribution based on the experimental parameters,thereby establishing a technical foundation for investigating the impact of experimental conditions on fuel cells.This model is also of great significance for research on fuel cell system control strategies and fault diagnosis. 展开更多
关键词 Proton exchange membrane fuel cell Segmented measurement device Current distribution Conditional variational auto-encoder
在线阅读 下载PDF
Muntz Rational Approximation for Special Function Classes in Orlicz Spaces 被引量:1
17
作者 Ruifang Yu Garide Wu 《Analysis in Theory and Applications》 CSCD 2017年第1期20-28,共9页
Using the method of construction, with the help of inequalities, we research the Muntz rational approximation of two kinds of special function classes, and give the corresponding estimates of approximation rates of th... Using the method of construction, with the help of inequalities, we research the Muntz rational approximation of two kinds of special function classes, and give the corresponding estimates of approximation rates of these classes under widely con- ditions. Because of the Orlicz Spaces is bigger than continuous function space and the Lp space, so the results of this paper has a certain expansion significance. 展开更多
关键词 Muntz rational approximation bounded variation function class Sobolev functionclass Orlicz space.
在线阅读 下载PDF
MNTZ RATIONAL APPROXIMATION FOR SPECIAL FUNCTION CLASSES IN Ba[0,1] SPACES
18
作者 Zhenghua Kang Garidi Wu 《Analysis in Theory and Applications》 2012年第1期87-94,共8页
In this paper, we research the Miintz rational approximation of two kinds of spe- cial function classes, and give the corresponding estimates of approximation rates of these classes.
关键词 Muntz rational approximation bounded variation function class Sobolevfunction class approximation rate
在线阅读 下载PDF
Predicting the Antigenic Variant of Human Influenza A(H3N2) Virus with a Stacked Auto-Encoder Model
19
作者 Zhiying Tan Kenli Li +1 位作者 Taijiao Jiang Yousong Peng 《国际计算机前沿大会会议论文集》 2017年第2期71-73,共3页
The influenza virus changes its antigenicity frequently due to rapid mutations, leading to immune escape and failure of vaccination. Rapid determination of the influenza antigenicity could help identify the antigenic ... The influenza virus changes its antigenicity frequently due to rapid mutations, leading to immune escape and failure of vaccination. Rapid determination of the influenza antigenicity could help identify the antigenic variants in time. Here, we built a stacked auto-encoder (SAE) model for predicting the antigenic variant of human influenza A(H3N2) viruses based on the hemagglutinin (HA) protein sequences. The model achieved an accuracy of 0.95 in five-fold cross-validations, better than the logistic regression model did. Further analysis of the model shows that most of the active nodes in the hidden layer reflected the combined contribution of multiple residues to antigenic variation. Besides, some features (residues on HA protein) in the input layer were observed to take part in multiple active nodes, such as residue 189, 145 and 156, which were also reported to mostly determine the antigenic variation of influenza A(H3N2) viruses. Overall,this work is not only useful for rapidly identifying antigenic variants in influenza prevention, but also an interesting attempt in inferring the mechanisms of biological process through analysis of SAE model, which may give some insights into interpretation of the deep learning 展开更多
关键词 Stacked auto-encoder Antigenic variatION nfluenza Machine learning
在线阅读 下载PDF
随机退化路网中多用户随机均衡的绝对效率损失
20
作者 张俊婷 朱文龙 陈华友 《武汉理工大学学报(信息与管理工程版)》 2025年第4期457-463,共7页
为了提高城市交通网络的运行效率,量化随机退化路网的效率损失具有重要意义。首先,在收费策略下,基于出行者具有时间价值的异质性,对路网中所有用户进行分类。其次,利用随机用户均衡原理来刻画出行者路径选择行为;在随机退化路网中,在... 为了提高城市交通网络的运行效率,量化随机退化路网的效率损失具有重要意义。首先,在收费策略下,基于出行者具有时间价值的异质性,对路网中所有用户进行分类。其次,利用随机用户均衡原理来刻画出行者路径选择行为;在随机退化路网中,在时间和费用准则下,基于变分法构建多用户类随机均衡模型;当以出行者感知总成本度量系统最优、且不包括道路收费时,建立多用户类随机系统最优模型。随后,相对于随机系统最优,界定了多用户类随机均衡的绝对效率损失。利用放缩法,推导获得绝对效率损失上界。再次,当路段特性函数为BPR情形,通过自由流时间参数的引入,获得了更紧的绝对效率损失上界。最后,通过算例验证结论的有效性。结果表明:双准则下绝对效率损失上界,不仅与路段特性函数类、出行者的时间价值、道路收费有关,还与多用户类随机交通均衡、多用户类随机系统最优下系统总出行时间有关。研究结果可为交通管理者制定科学的交通管控策略,从而实现降低系统效率损失的目标,提供理论支撑。 展开更多
关键词 城市交通 绝对效率损失 变分不等式 多用户随机均衡 随机退化路网
在线阅读 下载PDF
上一页 1 2 6 下一页 到第
使用帮助 返回顶部