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An Immune-Inspired Approach with Interval Allocation in Solving Multimodal Multi-Objective Optimization Problems with Local Pareto Sets
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作者 Weiwei Zhang Jiaqiang Li +2 位作者 Chao Wang Meng Li Zhi Rao 《Computers, Materials & Continua》 SCIE EI 2024年第6期4237-4257,共21页
In practical engineering,multi-objective optimization often encounters situations where multiple Pareto sets(PS)in the decision space correspond to the same Pareto front(PF)in the objective space,known as Multi-Modal ... In practical engineering,multi-objective optimization often encounters situations where multiple Pareto sets(PS)in the decision space correspond to the same Pareto front(PF)in the objective space,known as Multi-Modal Multi-Objective Optimization Problems(MMOP).Locating multiple equivalent global PSs poses a significant challenge in real-world applications,especially considering the existence of local PSs.Effectively identifying and locating both global and local PSs is a major challenge.To tackle this issue,we introduce an immune-inspired reproduction strategy designed to produce more offspring in less crowded,promising regions and regulate the number of offspring in areas that have been thoroughly explored.This approach achieves a balanced trade-off between exploration and exploitation.Furthermore,we present an interval allocation strategy that adaptively assigns fitness levels to each antibody.This strategy ensures a broader survival margin for solutions in their initial stages and progressively amplifies the differences in individual fitness values as the population matures,thus fostering better population convergence.Additionally,we incorporate a multi-population mechanism that precisely manages each subpopulation through the interval allocation strategy,ensuring the preservation of both global and local PSs.Experimental results on 21 test problems,encompassing both global and local PSs,are compared with eight state-of-the-art multimodal multi-objective optimization algorithms.The results demonstrate the effectiveness of our proposed algorithm in simultaneously identifying global Pareto sets and locally high-quality PSs. 展开更多
关键词 Multimodal multi-objective optimization problem local PSs immune-inspired reproduction
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IMMUNOCHEMICAL IDENTIFICATION AND LOCALIZATION OF CYTOCHROME P-450HSjISOZYME, AN ENZYME RELATED TO NITROSAMINE METABOLISM, IN HUMAN GASTRIC MUCOSA AND GASTRIC CARCINOMA
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作者 方策 沈云英 +1 位作者 吴德丰 潘秀森 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 1989年第2期19-23,共5页
Monoclonal antibody (MAb) to rat liver cyto-chrome P-450j isozyme, an activating enzyme specific to nitrosamine metabolism, was used coupled with immunoblotting, densitometer scanning of SDS-PAGE gels and immunohistoc... Monoclonal antibody (MAb) to rat liver cyto-chrome P-450j isozyme, an activating enzyme specific to nitrosamine metabolism, was used coupled with immunoblotting, densitometer scanning of SDS-PAGE gels and immunohistochemical technique. The trace P-450HSj isozyme (Mr. 51.5 Kd) was found in human gastric mucosa. It was similar to P-450j in molecular weight, catalytic and immunochemical properties. The concentrations of P-450HSj in mucosa of lesser curvature were higher than those in greater curvature. This might be one of the important reasons that lesser curvature is the commonest area for gastric carcinoma. But there was possibly less P-450HSj in gastric mucosa with cancer. Im-munohistochemically, P-450HSj was discovered in the cytoplasm of some glandular epithelial cells, especially in the glands with hyperplastic and intestinal metaplastic changes adjacent to carcinoma. It was also found in some normal glands and in tumor cells of high-differentiated adenocarcinoma, but not in those of low-differentiated ones. Following subjects are discussed: (1) the method of detecting trace P-450HSj, (2) the rule of distribution of P-450HSj, and (3) the relationship between the isozyme and the occurrence of gastric cancer caused by nitrosa-mines. 展开更多
关键词 IN HUMAN GASTRIC MUCOSA AND GASTRIC CARCINOMA AN ENZYME RELATED TO NITROSAMINE METABOLISM IMMUNOCHEMICAL identification AND localization OF CYTOCHROME P-450HSjISOZYME NDEA
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Research of Physical Parameter Identification and Damage Localization based on the Gibbs Sampling
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作者 Ziyan Wu Zongming Cai Shukui Liu 《建筑工程(中英文版)》 2017年第1期1-6,共6页
A new method for structural physical parameter identification is proposed for linear structure.Firstly,a linear structural identification model was obtained based on a series of transformation of the dynamic character... A new method for structural physical parameter identification is proposed for linear structure.Firstly,a linear structural identification model was obtained based on a series of transformation of the dynamic characteristic equation.Then the posterior distribution of the model is obtained by the Bayesian updating theory.Using the structural modal parameters and considering their randomness,the structural stiffness parameter is obtained from the conditional posterior distribution of the linear structural identification model.The Gibbs sampling based on the Markov Chain Monte Carlo(MCMC)method is employed during the process.In order to illustrate the proposed method,a 3-DOF linear shear building is used as an example to detect and quantify its damage based on model data measured before and after a severe loading event.The research shows that damage level and locations can be identified with little error by using proposed method. 展开更多
关键词 PHYSICAL PARAMETERS identification DAMAGE localization MCMC METHOD Gibbs Sampling
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Evolutionary Multitasking With Global and Local Auxiliary Tasks for Constrained Multi-Objective Optimization 被引量:3
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作者 Kangjia Qiao Jing Liang +3 位作者 Zhongyao Liu Kunjie Yu Caitong Yue Boyang Qu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第10期1951-1964,共14页
Constrained multi-objective optimization problems(CMOPs) include the optimization of objective functions and the satisfaction of constraint conditions, which challenge the solvers.To solve CMOPs, constrained multi-obj... Constrained multi-objective optimization problems(CMOPs) include the optimization of objective functions and the satisfaction of constraint conditions, which challenge the solvers.To solve CMOPs, constrained multi-objective evolutionary algorithms(CMOEAs) have been developed. However, most of them tend to converge into local areas due to the loss of diversity. Evolutionary multitasking(EMT) is new model of solving complex optimization problems, through the knowledge transfer between the source task and other related tasks. Inspired by EMT, this paper develops a new EMT-based CMOEA to solve CMOPs, in which the main task, a global auxiliary task, and a local auxiliary task are created and optimized by one specific population respectively. The main task focuses on finding the feasible Pareto front(PF), and global and local auxiliary tasks are used to respectively enhance global and local diversity. Moreover, the global auxiliary task is used to implement the global search by ignoring constraints, so as to help the population of the main task pass through infeasible obstacles. The local auxiliary task is used to provide local diversity around the population of the main task, so as to exploit promising regions. Through the knowledge transfer among the three tasks, the search ability of the population of the main task will be significantly improved. Compared with other state-of-the-art CMOEAs, the experimental results on three benchmark test suites demonstrate the superior or competitive performance of the proposed CMOEA. 展开更多
关键词 Constrained multi-objective optimization evolutionary multitasking(EMT) global auxiliary task knowledge transfer local auxiliary task
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I-beam Crack Identification Based on Study of Local Flexibility due to Crack 被引量:3
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作者 LI Bing CHEN Xuefeng HE Zhengjia 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第6期1116-1122,共7页
Local flexibility of crack plays an important role in crack identification of structures.Analytical methods on local flexibility in a cracked beam with simple geometric crossing sections,such as rectangle,circle,have ... Local flexibility of crack plays an important role in crack identification of structures.Analytical methods on local flexibility in a cracked beam with simple geometric crossing sections,such as rectangle,circle,have been made,but there are some difficulties in calculating local flexibility in a cracked beam with complex crossing section,such as pipe and I-beam.In this paper,an analytical method to calculate the local flexibility and rotational spring stiffness due to crack in I-beam is proposed.The local flexibility with respect to various crack depths can be calculated by dividing a cracked I-beam into a series of thin rectangles.The forward and inverse problems in crack detection of I-beam are studied.The forward problem comprises the construction of crack model exclusively for crack section and the construction of a numerically I-beam model to gain crack detection database.The inverse problem consists of the measurement of modal parameters and the detection of crack parameters.Two experiments including measurement of rotational spring stiffness and prediction of cracks in I-beam are conducted.Experimental results based on the current methods indicate that relative error of crack location is less than 3%,while the error of crack depth identification is less than 6%.Crack identification of I-beam is expected to contribute to the development of automated crack detection techniques for railway lines and building skeletons. 展开更多
关键词 CRACK identification I-BEAM local flexibility
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Multi-Innovation Gradient Iterative Locally Weighted Learning Identification for A Nonlinear Ship Maneuvering System 被引量:2
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作者 BAI Wei-wei REN Jun-sheng LI Tie-shan 《China Ocean Engineering》 SCIE EI CSCD 2018年第3期288-300,共13页
This paper explores a highly accurate identification modeling approach for the ship maneuvering motion with fullscale trial. A multi-innovation gradient iterative(MIGI) approach is proposed to optimize the distance me... This paper explores a highly accurate identification modeling approach for the ship maneuvering motion with fullscale trial. A multi-innovation gradient iterative(MIGI) approach is proposed to optimize the distance metric of locally weighted learning(LWL), and a novel non-parametric modeling technique is developed for a nonlinear ship maneuvering system. This proposed method’s advantages are as follows: first, it can avoid the unmodeled dynamics and multicollinearity inherent to the conventional parametric model; second, it eliminates the over-learning or underlearning and obtains the optimal distance metric; and third, the MIGI is not sensitive to the initial parameter value and requires less time during the training phase. These advantages result in a highly accurate mathematical modeling technique that can be conveniently implemented in applications. To verify the characteristics of this mathematical model, two examples are used as the model platforms to study the ship maneuvering. 展开更多
关键词 multi-innovation gradient iterative(MIGI) locally weighted learning(LWL) identification nonlinearship maneuvering full-scale trial
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Supervised Feature Learning for Offline Writer Identification Using VLAD and Double Power Normalization
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作者 Dawei Liang Meng Wu Yan Hu 《Computers, Materials & Continua》 SCIE EI 2023年第7期279-293,共15页
As an indispensable part of identity authentication,offline writer identification plays a notable role in biology,forensics,and historical document analysis.However,identifying handwriting efficiently,stably,and quick... As an indispensable part of identity authentication,offline writer identification plays a notable role in biology,forensics,and historical document analysis.However,identifying handwriting efficiently,stably,and quickly is still challenging due to the method of extracting and processing handwriting features.In this paper,we propose an efficient system to identify writers through handwritten images,which integrates local and global features from similar handwritten images.The local features are modeled by effective aggregate processing,and global features are extracted through transfer learning.Specifically,the proposed system employs a pre-trained Residual Network to mine the relationship between large image sets and specific handwritten images,while the vector of locally aggregated descriptors with double power normalization is employed in aggregating local and global features.Moreover,handwritten image segmentation,preprocessing,enhancement,optimization of neural network architecture,and normalization for local and global features are exploited,significantly improving system performance.The proposed system is evaluated on Computer Vision Lab(CVL)datasets and the International Conference on Document Analysis and Recognition(ICDAR)2013 datasets.The results show that it represents good generalizability and achieves state-of-the-art performance.Furthermore,the system performs better when training complete handwriting patches with the normalization method.The experimental result indicates that it’s significant to segment handwriting reasonably while dealing with handwriting overlap,which reduces visual burstiness. 展开更多
关键词 Writer identification power normalization vector of locally aggregated descriptors feature extraction
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Identification of LPV system using locally weighted technique
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作者 ZENG Jiu-sun GAO Chuan-hou LUO Shi-hua 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2010年第4期411-419,共9页
The problem of linear parameter varying (LPV) system identification is considered based on the locally weighted technique which provides estimation of the LPV model parameters at each distinct data time point by giv... The problem of linear parameter varying (LPV) system identification is considered based on the locally weighted technique which provides estimation of the LPV model parameters at each distinct data time point by giving large weights to measurements that are "close" to the current time point and small weights to measurements "far" from the current time point. Issues such as choice of distance function, weighting function and bandwidth selection are discussed. The developed method is easy to implement and simulation results illustrate its efficiency. 展开更多
关键词 Linear parameter varying system locally weighted technique identification.
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Numerical-Experimental Updating Identification of Elastic Behavior of a Composite Plate Using New Multi-Objective Optimization Procedure
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作者 Samir Ghanmi Sofiane Bouajila Mohamed Guedri 《Journal of Surface Engineered Materials and Advanced Technology》 2013年第1期13-20,共8页
This work focuses on the updating-based identification of the three-dimensional orthotropic elastic behavior of a thin carbon fiber reinforced plastic multilayer composite plate. This consists in identifying the engin... This work focuses on the updating-based identification of the three-dimensional orthotropic elastic behavior of a thin carbon fiber reinforced plastic multilayer composite plate. This consists in identifying the engineering constants that minimize the relative deviations between the first eight experimental and three-dimensional finite element frequencies of the vibrating free plate. For this purpose, a multi-objective optimization procedure is applied;it exploits a Particle Swarm Optimizer algorithm (PSO) that is coupled to a metamodeling by the new response surfaces method procedure (NRSMP);the latter is based on numerical design experiments. The conducted sensitivity analyses indicate that the four engineering constants of the two-dimensional elasticity are the most influent. 展开更多
关键词 Composites FINITE Element EXPERIMENTAL DESIGNS multi-objectIVE Optimization Numerical-Experimental Updating identification Response Surfaces
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Automated detection and identification of white-backed planthoppers in paddy fields using image processing 被引量:14
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作者 YAO Qing CHEN Guo-te +3 位作者 WANG Zheng ZHANG Chao YANG Bao-jun TANG Jian 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2017年第7期1547-1557,共11页
A survey of the population densities of rice planthoppers is important for forecasting decisions and efficient control. Tra- ditional manual surveying of rice planthoppers is time-consuming, fatiguing, and subjective.... A survey of the population densities of rice planthoppers is important for forecasting decisions and efficient control. Tra- ditional manual surveying of rice planthoppers is time-consuming, fatiguing, and subjective. A new three-layer detection method was proposed to detect and identify white-backed planthoppers (WBPHs, Sogatella furcifera (Horvath)) and their developmental stages using image processing. In the first two detection layers, we used an AdaBoost classifier that was trained on a histogram of oriented gradient (HOG) features and a support vector machine (SVM) classifier that was trained on Gabor and Local Binary Pattern (LBP) features to detect WBPHs and remove impurities. We achieved a detection rate of 85.6% and a false detection rate of 10.2%. In the third detection layer, a SVM classifier that was trained on the HOG features was used to identify the different developmental stages of the WBPHs, and we achieved an identification rate of 73.1%, a false identification rate of 23.3%, and a 5.6% false detection rate for the images without WBPHs. The proposed three-layer detection method is feasible and effective for the identification of different developmental stages of planthoppers on rice plants in paddy fields. 展开更多
关键词 white-backed planthopper developmental stage automated detection and identification image processing histogram of oriented gradient features gabor features local binary pattern features
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Research on mode localization of reticulated shell structures 被引量:4
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作者 Yan Weiming Wang Zhuo He Haoxiang 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2011年第1期75-84,共10页
Reticulated shell structures (RSSs) are characterized as cyclically periodic structures. Mistuning of RSSs will induce structural mode localization. Mode localization has the following two features: some modal vect... Reticulated shell structures (RSSs) are characterized as cyclically periodic structures. Mistuning of RSSs will induce structural mode localization. Mode localization has the following two features: some modal vectors of the structure change remarkably when the values of its physical parameters (mass or stiffness) have a slight change; and the vibration of some modes is mainly restricted in some local areas of the structure. In this paper, two quantitative assessment indexes are introduced that correspond to these two features. The first feature is studied through a numerical example of a RSS, and its induced causes are analyzed by using the perturbation theory. The analysis showed that internally, mode localization is closely related to structural frequencies and externally, slight changes of the physical parameters of the structure cause instability to the RSS. A scaled model experiment to examine mode localization was carried out on a Kiewit single-layer spherical RSS, and both features of mode localization are studied. Eight tests that measured the changes of the physical parameters were carried out in the experiment. Since many modes make their contribution in structural dynamic response, six strong vibration modes were tested at random in the experimental analysis. The change and localization of the six modes are analyzed for each test. The results show that slight changes to the physical parameters are likely to induce remarkable changes and localization of some modal vectors in the RSSs. 展开更多
关键词 reticulated shell structure mistuning mode localization perturbation theory seismic performance analysis damage identification
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A Mobile Localization Strategy for Wireless Sensor Network in NLOS Conditions 被引量:7
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作者 Long Cheng Yan Wang +2 位作者 Xingming Sun Nan Hu Jian Zhang 《China Communications》 SCIE CSCD 2016年第10期69-78,共10页
The problem of mobile localization for wireless sensor network has attracted considerable attention in recent years. The localization accuracy will drastically grade in non-line of sight(NLOS) conditions. In this pape... The problem of mobile localization for wireless sensor network has attracted considerable attention in recent years. The localization accuracy will drastically grade in non-line of sight(NLOS) conditions. In this paper, we propose a mobile localization strategy based on Kalman filter. The key technologies for the proposed method are the NLOS identification and mitigation. The proposed method does not need the prior knowledge of the NLOS error and it is independent of the physical measurement ways. Simulation results show that the proposed method owns the higher localization accuracy when compared with other methods. 展开更多
关键词 wireless sensor network localization non-line of sight identification MITIGATION
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Use of species-specific PCR for the identification of 10 sea cucumber species 被引量:3
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作者 文菁 曾玲 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2014年第6期1257-1263,共7页
We developed a species-specific PCR method to identify species among dehydrated products of 10 sea cucumber species.Ten reverse species-specific primers designed from the 16 S rRNA gene,in combination with one forward... We developed a species-specific PCR method to identify species among dehydrated products of 10 sea cucumber species.Ten reverse species-specific primers designed from the 16 S rRNA gene,in combination with one forward universal primer,generated PCR fragments of ca.270 bp length for each species.The specificity of the PCR assay was tested with DNA of samples of 21 sea cucumber species.Amplification was observed in specific species only.The species-specific PCR method we developed was successfully applied to authenticate species of commercial products of dehydrated sea cucumber,and was proven to be a useful,rapid,and low-cost technique to identify the origin of the sea cucumber product. 展开更多
关键词 sea cucumber dried product basic local alignment search tool (BLAST) species-specific PCR identification
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Localization of pallets in warehouses using passive RFID system 被引量:2
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作者 周俊儒 张宏建 周洪亮 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第8期3017-3025,共9页
Warehouse operation has become a critical activity in supply chain. Position information of pallets is important in warehouse management which can enhance the efficiency of pallets picking and sortation. Radio frequen... Warehouse operation has become a critical activity in supply chain. Position information of pallets is important in warehouse management which can enhance the efficiency of pallets picking and sortation. Radio frequency identification(RFID) has been widely used in warehouse for item identifying. Meanwhile, RFID technology also has great potential for pallets localization which is underutilized in warehouse management. RFID-based checking-in and inventory systems have been applied in warehouse management by many enterprises. Localization approach is studied, which is compatible with existing RFID checking-in and inventory systems. A novel RFID localization approach is proposed for pallets checking-in. Phase variation of nearby tags was utilized to estimate the position of added pallets. A novel inventory localization approach combing angle of arrival(AOA) measurement and received signal strength(RSS) is also proposed for pallets inventory. Experiments were carried out using standard UHF passive RFID system. Experimental results show an acceptable localization accuracy which can satisfy the requirement of warehouse management. 展开更多
关键词 warehouse management radio frequency identification (RFID) localization tag phase
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Coevolutionary Framework for Generalized Multimodal Multi-Objective Optimization 被引量:3
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作者 Wenhua Li Xingyi Yao +3 位作者 Kaiwen Li Rui Wang Tao Zhang Ling Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第7期1544-1556,共13页
Most multimodal multi-objective evolutionary algorithms(MMEAs)aim to find all global Pareto optimal sets(PSs)for a multimodal multi-objective optimization problem(MMOP).However,in real-world problems,decision makers(D... Most multimodal multi-objective evolutionary algorithms(MMEAs)aim to find all global Pareto optimal sets(PSs)for a multimodal multi-objective optimization problem(MMOP).However,in real-world problems,decision makers(DMs)may be also interested in local PSs.Also,searching for both global and local PSs is more general in view of dealing with MMOPs,which can be seen as generalized MMOPs.Moreover,most state-of-theart MMEAs exhibit poor convergence on high-dimension MMOPs and are unable to deal with constrained MMOPs.To address the above issues,we present a novel multimodal multiobjective coevolutionary algorithm(Co MMEA)to better produce both global and local PSs,and simultaneously,to improve the convergence performance in dealing with high-dimension MMOPs.Specifically,the Co MMEA introduces two archives to the search process,and coevolves them simultaneously through effective knowledge transfer.The convergence archive assists the Co MMEA to quickly approach the Pareto optimal front.The knowledge of the converged solutions is then transferred to the diversity archive which utilizes the local convergence indicator and the-dominance-based method to obtain global and local PSs effectively.Experimental results show that Co MMEA is competitive compared to seven state-of-the-art MMEAs on fifty-four complex MMOPs. 展开更多
关键词 Coevolution ∈-dominance generalized multimodal multi-objective optimization(MMO) local convergence two archives
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Identification Model for Needy Undergraduates Based on FFM
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作者 Luwen Hu Xiaoyong Zhao +1 位作者 Shihao Fan Yufeng Gui 《Applied Mathematics》 2020年第1期8-22,共15页
In recent years, as the enrollment rate of Chinese colleges has increased year by year, the identification of needy undergraduates has become increasingly important. However, the traditional way to identify college st... In recent years, as the enrollment rate of Chinese colleges has increased year by year, the identification of needy undergraduates has become increasingly important. However, the traditional way to identify college students with financial difficulties mainly relies on manual review and collective voting, which easily causes subjectivity and randomness. To alleviate the problem above, this paper establishes an automatic identification model for needy undergraduates based on the 1842 questionnaires collected from undergraduates in WHUT. Firstly, this paper filters the questionnaire preliminary using the local outlier factor algorithm. Secondly, this paper combines mutual information, Spearman rank correlation coefficient and distance correlation coefficient by rank-sum ratio to select features for eliminating noise from irrelevant features. Thirdly, this paper trains filed-aware factor machine model and compares it with other models, such as Logistic Regression, SVM, etc. Eventually, this paper finds that filed-aware factor machine performers much better than other models in the identification of needy undergraduates, and prominent features affecting the identification of needy undergraduates are the year of the family income, cost of living provided parents, etc. 展开更多
关键词 local OUTLIER FACTOR Rank-Sum Ratio Field-Aware FACTOR Machine identification Model for Needy UNDERGRADUATES
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薄壁钢板局部屈曲关键问题研究进展
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作者 蔡健 万军 +3 位作者 龙跃凌 陈庆军 左志亮 何岸 《建筑结构》 北大核心 2024年第19期119-127,共9页
钢结构以及钢-混凝土组合结构由于其强度高、耗能能力好、施工方便等优异性能,被广泛应用于工程结构中。然而,随着高强度钢材的应用,薄壁钢板呈现薄壁化、宽厚比随着构件截面尺寸的增大而不断增大的趋势,由于工程结构及荷载的复杂性等因... 钢结构以及钢-混凝土组合结构由于其强度高、耗能能力好、施工方便等优异性能,被广泛应用于工程结构中。然而,随着高强度钢材的应用,薄壁钢板呈现薄壁化、宽厚比随着构件截面尺寸的增大而不断增大的趋势,由于工程结构及荷载的复杂性等因素,钢板过早发生局部屈曲的风险不断加大,薄壁钢板的局部屈曲问题凸显,亟待开展系统性深入研究。对薄壁钢板局部屈曲研究的进展进行了概述,分析总结了现有试验研究和理论研究方面存在的局限性,详细介绍了笔者团队近年来聚焦于薄壁钢板局部屈曲关键问题开展的一系列研究工作及成果。 展开更多
关键词 薄壁钢板 局部屈曲 局部屈曲判定 钢管混凝土 约束拉杆
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基于线阵相机/扫描仪的轨交隧道病害检测系统设计实现
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作者 石波 王慧超 +5 位作者 杨晓磊 李国玉 赵凯 王聪 杨密 林康 《电子测量与仪器学报》 CSCD 北大核心 2024年第6期181-194,共14页
隧道维护可以避免隧道病害引发的安全事故,有效的维护依赖于全面和准确的隧道病害检测。传统的隧道病害检测依靠人工巡检,受隧道照明不足、检测时间短等因素的影响,检测效率低下且准确率低。针对这些隧道病害检测中的难题,根据轨交隧道... 隧道维护可以避免隧道病害引发的安全事故,有效的维护依赖于全面和准确的隧道病害检测。传统的隧道病害检测依靠人工巡检,受隧道照明不足、检测时间短等因素的影响,检测效率低下且准确率低。针对这些隧道病害检测中的难题,根据轨交隧道结构均匀、轨道线路固定的特点设计了轨交隧道病害检测系统。系统将激光扫描技术与摄影测量技术相结合,使用激光扫描仪获取隧道三维点云,使用多线阵相机获取隧道影像,借助激光跟踪仪并设计虚拟靶标场对相机和扫描仪进行标定使其坐标基准统一。系统采用分布式的软件架构研发数据采集软件进行传感器交互和数据存储,并采用外触发的方法使传感器采集频率与车速匹配,最后基于Cesium框架研发数据管理平台对隧道数据进行管理。将系统应用于某隧道进行数据精度验证,实验表明轨交隧道病害检测系统能够在实际隧道中检测宽度为0.2 mm的裂缝和错台量0.5 mm的错台,具备轨交隧道病害检测能力。最后,通过将实验采集到的数据应用于隧道裂缝检测、错台检测、变形检测等方面,并对检测出的病害进行定位,证明了轨交隧道病害检测系统的实用性,为轨交隧道病害检测提供了可靠的解决方案。 展开更多
关键词 隧道病害 隧道病害检测系统 系统集成 病害识别 病害定位
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基于广义柔度曲率信息熵的板式轨道脱空损伤识别
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作者 刘渝 赵坪锐 +2 位作者 徐天赐 刘卫星 姚力 《铁道标准设计》 北大核心 2024年第4期48-54,62,共8页
板式轨道填充层作为轨道结构关键部位,在高频列车荷载和环境共同作用下出现脱空损伤,引起脱空位置轨道结构刚度改变。为有效检测板式轨道的轨道板脱空情况,采用数值仿真分析得到无砟轨道模态信息,利用轨道脱空区域广义柔度曲率局部峰值... 板式轨道填充层作为轨道结构关键部位,在高频列车荷载和环境共同作用下出现脱空损伤,引起脱空位置轨道结构刚度改变。为有效检测板式轨道的轨道板脱空情况,采用数值仿真分析得到无砟轨道模态信息,利用轨道脱空区域广义柔度曲率局部峰值进行轨道脱空损伤识别。结合广义柔度、均匀荷载面(Uniform load surface, ULS)、曲率和局部信息熵,提出可定位损伤的ULS曲率信息熵,并在CRTS III板式轨道上进行验证。研究结果表明:广义柔度曲率利用轨道脱空前后模态信息计算轨道脱空损伤曲率差,能够有效定位脱空位置;ULS曲率信息熵表征值只需要轨道的一阶模态信息便能够有效地反映轨道脱空位置及面积,且克服了广义柔度曲率需要健康模态信息的不足;轨道对称位置上相同面积脱空的ULS曲率信息熵值相同;ULS曲率信息熵值与脱空面积和厚度成正相关关系;ULS曲率信息熵表征值具有较好的损伤识别敏感性,能够识别小于单个测点布置面积的0.1 m×0.1 m小面积脱空,并且对轨道板边脱空识别敏感性高于轨道板中脱空识别敏感性。 展开更多
关键词 板式无砟轨道 广义柔度 均匀荷载面 局部信息熵 损伤识别
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图采样泛化行人重识别算法
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作者 闵锋 毛一新 +3 位作者 况永刚 彭伟明 郝琳琳 吴波 《计算机工程与应用》 CSCD 北大核心 2024年第14期219-227,共9页
最近的研究表明,度量学习中的深度特征匹配方法,结合大规模、多样化的训练数据,可以显著增强人员再识别的泛化能力。然而,许多现有的方法会产生大量的内存和计算成本,如分类参数或类记忆学习等。为解决上述问题,提出了一种新的基于相关... 最近的研究表明,度量学习中的深度特征匹配方法,结合大规模、多样化的训练数据,可以显著增强人员再识别的泛化能力。然而,许多现有的方法会产生大量的内存和计算成本,如分类参数或类记忆学习等。为解决上述问题,提出了一种新的基于相关性图采样(correlation graph sampler,CGS)的泛化行人重识别算法,CGS的基本思想是在训练开始时使用局部敏感哈希函数(locality-sensitive Hashing,LSH)和特征度量为所有类构造最近邻关系图。这确保了每一小批训练样本由随机选择的基类和与基类具有相似性的近邻类组成,以提供信息量大且具有挑战性的学习示例,提高行人重识别模型的判别性学习能力。CGS的采样原理会受主干网提取的特征质量影响,因此CGS采样能力会随着主干网的训练而增强,具有可学习性。通过在大规模数据集(包括CUHK03、Market-1501和MSMT17)上交叉评估该方法,广泛的实验结果证实了该方法的有效性,并展示了其在行人重识别应用中的潜力。 展开更多
关键词 行人重识别 度量学习 相关性图采样 局部敏感哈希函数
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