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Optimization of multi-cluster fracturing in deep reservoirs based on stress field reconstruction effect 认领 引用 被引量：1
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作者 Jinbo Li Siwei Meng +3 位作者 He Liu Suling Wang Kangxing Dong Qiuyu Lu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第3期227-245,共19页
Since rock plasticity under in-situ conditions poses challenges during fracturing stimulation,extensive research is necessary on deep gas and oil reserves,which will be the primary area of future development.This pape... Since rock plasticity under in-situ conditions poses challenges during fracturing stimulation,extensive research is necessary on deep gas and oil reserves,which will be the primary area of future development.This paper created a competitive,multi-cluster fracture propagation model that considered elastoplastic rock deformation and nonlinear fracture characteristics in deep reservoirs.It also proposed an optimal fracture design of“dense fracture distribution,non-uniform perforation and alternating staged fracturing”based on stress field reconstruction.The findings indicated that suitably reducing the spacing between clusters and increasing the number of perforated clusters minimized local in-situ stress variations through stress interference among fractures.This mitigated the limiting effect of plastic deformation on the propagation of hydraulic fractures,demonstrating a viable approach for enhancing the expansion of fractures in deep reservoirs.The elastoplastic fracture propagation mechanism was examined to elucidate the advantages of close-cutting fracturing technology.The impact of various fracture techniques was analyzed using stress field reconstruction.Alternate fracturing displayed a high degree of stress reconstruction with an extensive propagation range,which facilitated the propagation of multiple fracture clusters in the subsequent fracturing section.The findings offer a theoretical basis for fracture design of deep reservoirs. 展开更多
关键词 Deep reservoir Stress field reconstruction Stage multi-cluster fracturing Elastoplastic crack Competitive propagation
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Research on the Competition Mechanism of Fractures in Multi-Cluster Fracturing of Horizontal Wells:Dynamic Response and Influence of Engineering Parameters 认领 引用
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作者 Pujin Wang Guofa Ji +1 位作者 Wenwei Zhao Liangping Yi 《Energy Engineering》 EI 2026年第5期195-211,共17页
In multi-cluster horizontal well fracturing,non-uniform propagation due to inter-cluster interference severely limits the effectiveness of reservoir stimulation.This study employs the discrete lattice method for numer... In multi-cluster horizontal well fracturing,non-uniform propagation due to inter-cluster interference severely limits the effectiveness of reservoir stimulation.This study employs the discrete lattice method for numerical simulation,investigating the influence of cluster spacing,fracturing fluid injection rate,and horizontal stress difference on fracture propagation morphology by monitoring,in real time,the dynamic changes in flow pressure,flow rate,and fluid intake volume for each cluster.The results indicate that the stress shadow effect is the fundamental cause of non-uniform fracture propagation.Cluster spacing is a key parameter controlling the maximum flow pressure difference between the central and edge clusters.When cluster spacing decreases from 4 to 2 m,the maximum flow pressure difference increases by 7.32 MPa,while the fluid intake volume decreases by nearly three times.Increasing the injection rate of the fracturing fluid raises the maximum fracture width from 7.35 to 15.1 mm and reduces the maximum inter-cluster flow pressure difference from 4.48 to 0.53 MPa.A reduction in the horizontal stress difference mitigates the stress shadow effect.When the horizontal stress difference decreases from 5 to 1 MPa,the maximum fracture width increases by 3.97 mm.This study elucidates the influence of various parameters on hydraulic fracturing effectiveness,providing theoretical guidance for optimizing fracturing parameters in fracture-propagation design. 展开更多
关键词 Horizontal well fracture competition numerical simulation multi-cluster fracturing dynamic response
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Fracture parameter diagnostic method during staged multi-cluster fracturing based on distributed temperature sensing 认领 引用 被引量：1
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作者 WEI Cao LI Haitao +4 位作者 ZHU Xiaohua ZHANG Nan LUO Hongwen TU Kun CHENG Shiqing 《Petroleum Exploration and Development》 SCIE 2025年第2期496-505,共10页
The Carter model is used to characterize the dynamic behaviors of fracture growth and fracturing fluid leakoff.A thermo-fluid coupling temperature response forward model is built considering the fluid flow and heat tr... The Carter model is used to characterize the dynamic behaviors of fracture growth and fracturing fluid leakoff.A thermo-fluid coupling temperature response forward model is built considering the fluid flow and heat transfer in wellbore,fracture and reservoir.The influences of fracturing parameters and fracture parameters on the responses of distributed temperature sensing(DTS)are analyzed,and a diagnosis method of fracture parameters is presented based on the simulated annealing algorithm.A field case study is introduced to verify the model’s reliability.Typical V-shaped characteristics can be observed from the DTS responses in the multi-cluster fracturing process,with locations corresponding to the hydraulic fractures.The V-shape depth is shallower for a higher injection rate and longer fracturing and shut-in time.Also,the V-shape is wider for a higher fracture-surface leakoff coefficient,longer fracturing time and smaller fracture width.Additionally,the cooling effect near the wellbore continues to spread into the reservoir during the shut-in period,causing the DTS temperature to decrease instead of rise.Real-time monitoring and interpretation of DTS temperature data can help understand the fracture propagation during fracturing operation,so that immediate measures can be taken to improve the fracturing performance. 展开更多
关键词 shale oil horizontal well multi-stage multi-cluster fracturing distributed temperature sensing thermo-fluid coupling model fracture parameters real-time monitoring
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Evaluating the scope of human leukocyte antigen polymorphisms influencing hepatitis B virus-related liver cancer and cirrhosis through multi-clustering analysis 认领 引用
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作者 Shi Li Yue Xi +3 位作者 Xue-Ying Dong Wen-Bin Yuan Jing-Feng Tang Ce-Fan Zhou 《World Journal of Gastroenterology》 SCIE CAS 2025年第7期156-159,共4页
Hepatitis B virus remains a major cause of cirrhosis and hepatocellular carcinoma,with genetic polymorphisms and mutations influencing immune responses and disease progression.Nguyen et al present novel findings on sp... Hepatitis B virus remains a major cause of cirrhosis and hepatocellular carcinoma,with genetic polymorphisms and mutations influencing immune responses and disease progression.Nguyen et al present novel findings on specific human leukocyte antigen(HLA)alleles,including rs2856718 of HLA-DQ and rs3077 and rs9277535 of HLA-DP,which may predispose individuals to cirrhosis and liver cancer,based on multi-clustering analysis.Here,we discuss the feasibility of this approach and identify key areas for further investigation,aiming to offer insights for advancing clinical practice and research in liver disease and related cancers. 展开更多
关键词 Hepatitis B virus Gene polymorphisms Multi-clustering analysis Genetic markers Personalized medicine Clinical implications
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Evolution of multi-cluster fracturing in high-density layered shale considering the effect of injection scheme 认领 引用
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作者 Xiao Yan Haitao Yu Peng Zhang 《Petroleum Science》 SCIE EI CAS CSCD 2025年第5期2109-2122,共14页
Shale oil reservoir is generally characterized by well-developed bedding planes,and multi-cluster fracturing is the most effective technique to achieve stable shale oil production.In this paper,a multi-cluster fractur... Shale oil reservoir is generally characterized by well-developed bedding planes,and multi-cluster fracturing is the most effective technique to achieve stable shale oil production.In this paper,a multi-cluster fracturing model for a horizontal well in shale with high-density bedding planes is established.The fracture morphology,fracture geometry,fracturing area and multiple fracture propagation mechanism are analyzed under simultaneous fracturing,sequential fracturing,and alternative fracturing.Results show that in the case of small cluster spacing and three clusters,the growth of the middle fracture is inhibited and develops along the bedding planes under both simultaneous fracturing and alternative fracturing.For sequential fracturing,the increase in the interval time between each fracturing advances the post fracturing fracture deflecting to the pre-existing fractures through the bedding planes.The reactivation of the bedding planes can promote the extension of the fracturing area.Increasing the injection rate and the number of clusters promotes the activation of bedding planes.However,it is preferable to reduce the number of clusters to obtain more main fractures.Compared with modified alternating fracturing and cyclic alternating fracturing,alternating shut-in fracturing creates more main fractures towards the direction of the maximum in-situ stress.The fracturing efficiency for high-density layered shale is ranked as simultaneous fracturing>alternative fracturing>sequential fracturing. 展开更多
关键词 Multi-cluster fracturing Bedding planes Fracture morphology Injection scheme Numerical simulation
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Polynomial Approach to Optimal One-wafer Cyclic Scheduling of Treelike Hybrid Multi-Cluster Tools via Petri Nets 认领 引用 被引量：10
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作者 Fajun Yang Naiqi Wu +1 位作者 Yan Qiao Rong Su 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第1期270-280,共11页
A treelike hybrid multi-cluster tool is composed of both single-arm and dual-arm cluster tools with a treelike topology. Scheduling such a tool is challenging. For a hybrid treelike multi-cluster tool whose bottleneck... A treelike hybrid multi-cluster tool is composed of both single-arm and dual-arm cluster tools with a treelike topology. Scheduling such a tool is challenging. For a hybrid treelike multi-cluster tool whose bottleneck individual tool is process-bound, this work aims at finding its optimal one-wafer cyclic schedule. It is modeled with Petri nets such that a onewafer cyclic schedule is parameterized as its robots' waiting time.Based on the model, this work proves the existence of its onewafer cyclic schedule that features with the ease of industrial implementation. Then, computationally efficient algorithms are proposed to find the minimal cycle time and optimal onewafer cyclic schedule. Multi-cluster tool examples are given to illustrate the proposed approach. The use of the found schedules enables industrial multi-cluster tools to operate with their highest productivity. 展开更多
关键词 Multi-cluster tool Petri nets scheduling semiconductor manufacturing
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Fracture propagation law of temporary plugging and diversion fracturing in shale reservoirs under completion experiments of horizontal well with multi-cluster sand jetting perforation 认领 引用 被引量：7
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作者 ZOU Yushi LI Yanchao +3 位作者 YANG Can ZHANG Shicheng MA Xinfang ZOU Longqing 《Petroleum Exploration and Development》 SCIE 2024年第3期715-726,共12页
This study conducted temporary plugging and diversion fracturing(TPDF)experiments using a true triaxial fracturing simulation system within a laboratory setting that replicated a lab-based horizontal well completion w... This study conducted temporary plugging and diversion fracturing(TPDF)experiments using a true triaxial fracturing simulation system within a laboratory setting that replicated a lab-based horizontal well completion with multi-cluster sand jetting perforation.The effects of temporary plugging agent(TPA)particle size,TPA concentration,single-cluster perforation number and cluster number on plugging pressure,multi-fracture diversion pattern and distribution of TPAs were investigated.A combination of TPAs with small particle sizes within the fracture and large particle sizes within the segment is conducive to increasing the plugging pressure and promoting the diversion of multi-fractures.The addition of fibers can quickly achieve ultra-high pressure,but it may lead to longitudinal fractures extending along the wellbore.The temporary plugging peak pressure increases with an increase in the concentration of the TPA,reaching a peak at a certain concentration,and further increases do not significantly improve the temporary plugging peak pressure.The breaking pressure and temporary plugging peak pressure show a decreasing trend with an increase in single-cluster perforation number.A lower number of single-cluster perforations is beneficial for increasing the breaking pressure and temporary plugging peak pressure,and it has a more significant control on the propagation of multi-cluster fractures.A lower number of clusters is not conducive to increasing the total number and complexity of artificial fractures,while a higher number of clusters makes it difficult to achieve effective plugging.The TPAs within the fracture is mainly concentrated in the complex fracture areas,especially at the intersections of fractures.Meanwhile,the TPAs within the segment are primarily distributed near the perforation cluster apertures which initiated complex fractures. 展开更多
关键词 shale temporary plugging and diversion fracturing multi-cluster sand jetting perforation distribution of temporary plugging agent fracture propagation law
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Optimal Integrated Schedule of Entire Process of Dual-blade Multi-cluster Tools From Start-up to Close-down 认领 引用 被引量：9
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作者 Qinghua Zhu Yan Qiao Naiqi Wu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2019年第2期553-565,共13页
Multi-cluster tools are widely used in majority of wafer fabrication processes in semiconductor industry. Smaller lot production, thinner circuit width in wafers, larger wafer size, and maintenance have resulted in a ... Multi-cluster tools are widely used in majority of wafer fabrication processes in semiconductor industry. Smaller lot production, thinner circuit width in wafers, larger wafer size, and maintenance have resulted in a large quantity of their start-up and close-down transient periods. Yet, most of existing efforts have been concentrated on scheduling their steady states.Different from such efforts, this work schedules their transient and steady-state periods subject to wafer residency constraints. It gives the schedulability conditions for the steady-state scheduling of dual-blade robotic multi-cluster tools and a corresponding algorithm for finding an optimal schedule. Based on the robot synchronization conditions, a linear program is proposed to figure out an optimal schedule for a start-up period, which ensures a tool to enter the desired optimal steady state. Another linear program is proposed to find an optimal schedule for a closedown period that evolves from the steady state period. Finally,industrial cases are presented to illustrate how the provided method outperforms the existing approach in terms of system throughput improvement. 展开更多
关键词 Multi-cluster tools robots scheduling transient periods semiconductor manufacturing systems
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Fractures interaction and propagation mechanism of multi-cluster fracturing on laminated shale oil reservoir 认领 引用 被引量：3
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作者 Jia-Xin Lv Bing Hou 《Petroleum Science》 SCIE EI CAS CSCD 2024年第4期2600-2613,共14页
The continental shale reservoirs of Jurassic Lianggaoshan Formation in Sichuan Basin contain thin lamina,which is characterized by strong plasticity and developed longitudinal shell limestone interlayer.To improve the... The continental shale reservoirs of Jurassic Lianggaoshan Formation in Sichuan Basin contain thin lamina,which is characterized by strong plasticity and developed longitudinal shell limestone interlayer.To improve the production efficiency of reservoirs by multi-cluster fracturing,it is necessary to consider the unbalanced propagation of hydraulic fractures and the penetration effect of fractures.This paper constructed a numerical model of multi-fracture propagation and penetration based on the finite element coupling cohesive zone method;considering the construction cluster spacing,pump rate,lamina strength and other parameters studied the influencing factors of multi-cluster fracture interaction propagation;combined with AE energy data and fracture mode reconstruction method,quantitatively characterized the comprehensive impact of the strength of thin interlayer rock interfaces on the initiation and propagation of fractures that penetrate layers,and accurately predicted the propagation pattern of hydraulic fractures through laminated shale oil reservoirs.Simulation results revealed that in the process of multi-cluster fracturing,the proportion of shear damage is low,and mainly occurs in bedding fractures activated by outer fractures.Reducing the cluster spacing enhances the fracture system's penetration ability,though it lowers the activation efficiency of lamina.The high plasticity of the limestone interlayer may impact the vertical propagation distance of the main fracture.Improving the interface strength is beneficial to the reconstruction of the fracture height,but the interface communication effect is limited.Reasonable selection of layers with moderate lamina strength for fracturing stimulation,increasing the pump rate during fracturing and setting the cluster spacing reasonably are beneficial to improve the effect of reservoir stimulation. 展开更多
关键词 Laminated shale Multi-cluster fracturing Cross-layer Cohesive zone model Acoustic emission technique
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Scheduling a Single-Arm Multi-Cluster Tool With a Condition-Based Cleaning Operation 认领 引用 被引量：1
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作者 Qinghua Zhu Hongpeng Li +1 位作者 Cong Wang Yan Hou 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第10期1965-1983,共19页
As wafer circuit widths shrink less than 10 nm,stringent quality control is imposed on the wafer fabrication processes. Therefore, wafer residency time constraints and chamber cleaning operations are widely required i... As wafer circuit widths shrink less than 10 nm,stringent quality control is imposed on the wafer fabrication processes. Therefore, wafer residency time constraints and chamber cleaning operations are widely required in chemical vapor deposition, coating processes, etc. They increase scheduling complexity in cluster tools. In this paper, we focus on scheduling single-arm multi-cluster tools with chamber cleaning operations subject to wafer residency time constraints. When a chamber is being cleaned, it can be viewed as processing a virtual wafer. In this way, chamber cleaning operations can be performed while wafer residency time constraints for real wafers are not violated. Based on such a method, we present the necessary and sufficient conditions to analytically check whether a single-arm multi-cluster tool can be scheduled with a chamber cleaning operation and wafer residency time constraints. An algorithm is proposed to adjust the cycle time for a cleaning operation that lasts a long cleaning time.Meanwhile, algorithms for a feasible schedule are also derived.And an algorithm is presented for operating a multi-cluster tool back to a steady state after the cleaning. Illustrative examples are given to show the application and effectiveness of the proposed method. 展开更多
关键词 Chamber cleaning multi-cluster tools scheduling semiconductor manufacturing
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Multi-clustering study on the association between human leukocyte antigen-DP-DQ and hepatitis B virus-related hepatocellular carcinoma and cirrhosis in Viet Nam 认领 引用 被引量：2
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作者 Thuy Thu Nguyen Tu Cam Ho +2 位作者 Huong Thi Thu Bui Van-Khanh Tran Tue Trong Nguyen 《World Journal of Gastroenterology》 SCIE CAS 2024年第46期4880-4903,共24页
BACKGROUND Human leukocyte antigen(HLA)class II molecules are cell surface receptor proteins found on antigen-presenting cells.Polymorphisms and mutations in the HLA gene can affect the immune system and the progressi... BACKGROUND Human leukocyte antigen(HLA)class II molecules are cell surface receptor proteins found on antigen-presenting cells.Polymorphisms and mutations in the HLA gene can affect the immune system and the progression of hepatitis B.AIM To study the relation between rs2856718 of HLA-DQ,rs3077,and rs9277535 of HLA-DP,hepatitis B virus(HBV)-related cirrhosis,and hepatocellular carcinoma(HCC).METHODS In this case-control study,the genotypes of these single nucleotide polymorphisms(SNPs)were screened in 315 healthy controls,471 chronic hepatitis B patients,250 patients with HBV-related liver cirrhosis,and 251 patients with HCC using TaqMan real-time PCR.We conducted Hardy-Weinberg equilibrium and linkage disequilibrium tests on the genotype distributions of rs2856718,rs3077,and rs9277535 before hierarchical clustering analysis to build the complex interaction between the markers in each patient group.RESULTS The physical distance separating these SNPs was 29816 kB with the disequilibrium(D’)values ranging from 0.07 to 0.34.The close linkage between rs3077 and rs9277535 was attributed to a distance of 21 kB.The D’value decreased from moderate in the healthy control group(D’=0.50,P<0.05)to weak in the hepatic disease group(D’<0.3,P<0.05).In a combination of the three variants rs2856718,rs3077,and rs9277535,the A allele decreased hepatic disease risk[A-A-A haplotype,risk ratio(RR)=0.44(0.14;1.37),P<0.05].The G allele had the opposite effect[G-A/G-G haplotype,RR=1.12(1.02;1.23),P<0.05].In liver cancer cases,the A-A-A/G haplotype increased the risk of HCC by 1.58(P<0.05).CONCLUSION Rs9277535 affects liver fibrosis progression due to HBV infection,while rs3077 is associated with a risk of HBVrelated HCC.The link between rs2856718,rs3077,and rs9277535 and disease risk was determined using a multiclustering analysis. 展开更多
关键词 Human leukocyte antigen Multi-clustering study Hepatitis B virus Hepatocellular carcinoma Cirrhosis
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Simulation Method and Feature Analysis of Shutdown Pressure Evolution During Multi-Cluster Fracturing Stimulation 认领 引用
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作者 Huaiyin He Longqing Zou +5 位作者 Yanchao Li Yixuan Wang Junxiang Li Huan Wen Bei Chang Lijun Liu 《Energy Engineering》 EI 2024年第1期111-123,共13页
Multistage multi-cluster hydraulic fracturing has enabled the economic exploitation of shale reservoirs,but the interpretation of hydraulic fracture parameters is challenging.The pressure signals after pump shutdown a... Multistage multi-cluster hydraulic fracturing has enabled the economic exploitation of shale reservoirs,but the interpretation of hydraulic fracture parameters is challenging.The pressure signals after pump shutdown are influenced by hydraulic fractures,which can reflect the geometric features of hydraulic fracture.The shutdown pressure can be used to interpret the hydraulic fracture parameters in a real-time and cost-effective manner.In this paper,a mathematical model for shutdown pressure evolution is developed considering the effects of wellbore friction,perforation friction and fluid loss in fractures.An efficient numerical simulation method is established by using the method of characteristics.Based on this method,the impacts of fracture half-length,fracture height,opened cluster and perforation number,and filtration coefficient on the evolution of shutdown pressure are analyzed.The results indicate that a larger fracture half-length may hasten the decay of shutdown pressure,while a larger fracture height can slow down the decay of shutdown pressure.A smaller number of opened clusters and perforations can significantly increase the perforation friction and decrease the overall level of shutdown pressure.A larger filtration coefficient may accelerate the fluid filtration in the fracture and hasten the drop of the shutdown pressure.The simulation method of shutdown pressure,as well as the analysis results,has important implications for the interpretation of hydraulic fracture parameters. 展开更多
关键词 Multistage multi-cluster hydraulic fracturing pump shutdown pressure feature analysis numerical simulation
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Multi-Cluster Flocking Behavior Analysis for a Delayed Cucker-Smale Model with Short-Range Communication Weight 认领 引用 被引量：2
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作者 QIAO Zhengyang LIU Yicheng WANG Xiao 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2022年第1期137-158,共22页
This paper analyzes the multi-cluster flocking behavior of a Cucker-Smale model involving delays and a short-range communication weight.In each sub-flocking group,the velocity between agents is alignment and the posit... This paper analyzes the multi-cluster flocking behavior of a Cucker-Smale model involving delays and a short-range communication weight.In each sub-flocking group,the velocity between agents is alignment and the position locates at a limited domain;but in different sub-flocking groups,the position between agents is unbounded.By constructing dissipative differential inequalities of subensembles together with Lyapunov functional methods,the authors provide the sufficient condition for the multi-cluster flocking emerging.The sufficient condition includes the estimation of the range of coupling strength and the upper bound of time delay.As a result,the authors show that the coupling strength among agents and initial threshold value determine the multi-cluster flocking behavior of the delayed Cucker-Smale model. 展开更多
关键词 Cucker-Smale model Lyapunov functional multi-cluster flocking short-range communication weight time-delay systems
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基于锚点加速机制的聚类算法综述 认领 引用 被引量：2
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作者 吴沁停 封与哲 +3 位作者 潘金艳 张海峰 曹超 高云龙 《上海交通大学学报》 EI CAS CSCD 北大核心 2026年第5期705-724,共20页
随着大数据时代的到来,聚类算法已成为数据挖掘和机器学习的关键.数据规模和维度的指数级增长导致传统聚类方法的时间和空间复杂性不断升级,制约了其实际应用.为应对这些挑战,锚点加速机制应运而生,显著减轻计算负担,提高传统聚类算法... 随着大数据时代的到来,聚类算法已成为数据挖掘和机器学习的关键.数据规模和维度的指数级增长导致传统聚类方法的时间和空间复杂性不断升级,制约了其实际应用.为应对这些挑战,锚点加速机制应运而生,显著减轻计算负担,提高传统聚类算法在大规模数据集上的有效性.全面回顾基于锚点加速机制的聚类算法,探讨锚点生成和相似性图构建等技术,涵盖利用固定锚点的聚类方法,包括谱聚类、模糊谱聚类、多视图聚类和深度聚类.研究采用动态锚点的聚类策略,包括多视图和不完全多视图聚类算法.通过综合分析,指出当前基于锚点加速机制算法研究的局限性,并直面新挑战,对未来的发展方向提出见解,为指导该领域的后续研究和实际应用提供路线图,促进适合当代数据环境的聚类算法的持续创新. 展开更多
关键词 聚类 锚点 谱聚类 模糊聚类 多视图聚类 深度聚类
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基于交替中心聚类的无监督跨模态行人重识别 认领 引用 被引量：2
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作者 陈峰 李果 +1 位作者 何结龙 刘阳 《华中科技大学学报（自然科学版）》 EI CAS CSCD 北大核心 2026年第5期54-60,共7页
针对现有无监督跨模态行人重识别方法在聚类过程中通常仅对各模态数据进行独立聚类,难以有效建立跨模态关联的难题,提出一种交替中心聚类策略与优化方法.首先,对不同模态的数据分别进行模态内聚类以形成初始类簇;然后,利用该初始类簇的... 针对现有无监督跨模态行人重识别方法在聚类过程中通常仅对各模态数据进行独立聚类,难以有效建立跨模态关联的难题,提出一种交替中心聚类策略与优化方法.首先,对不同模态的数据分别进行模态内聚类以形成初始类簇;然后,利用该初始类簇的先验信息,通过交替选择不同模态类簇中心作为全局数据初始类簇中心进行二次聚类,从而构建跨模态类簇关联.此外,设计了混合对比学习框架,用于进一步减小模态间差异,通过构建混合聚类中心联合学习模态特定信息和模态不变信息,以优化跨模态特征表达.实验结果表明:本研究模型在SYSU-MM01和RegDB数据集上的两种模式下,相对于基线模型mAP指标分别取得了7.09%,5.89%和18.52%,18.30%的性能提升. 展开更多
关键词 无监督学习 行人重识别 多模态聚类 对比学习 特征表示
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基于闭环聚类和多目标优化的风电短期功率预测方法 认领 引用 被引量：2
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作者 郭琦 闫军 +5 位作者 郝乾鹏 韩东 杨志豪 闫馨月 张海鹏 李然 《上海交通大学学报》 EI CAS CSCD 北大核心 2026年第2期246-255,共10页
在区域风电短期功率组合预测领域,常用深度学习预测模型虽然能够充分学习各单一模型的预测特征,但样本数据规模较小时,深度学习模型容易对训练数据分布产生依赖,从而产生过拟合现象;此外,虽然聚类方法被用来提升区域级预测的精度,但现... 在区域风电短期功率组合预测领域,常用深度学习预测模型虽然能够充分学习各单一模型的预测特征,但样本数据规模较小时,深度学习模型容易对训练数据分布产生依赖,从而产生过拟合现象;此外,虽然聚类方法被用来提升区域级预测的精度,但现有方法的聚类目标通常为不同类中风电场的差异最小化,而未考虑与预测目标的一致性.为解决以上问题,提出一种基于闭环聚类和多目标优化的风电短期功率预测方法.首先,通过闭环聚类算法将风电场分为多类;对于每类中的风电场数据,运用Bootstrap方法从原始数据集中随机有放回地抽取N组训练子集;然后,利用N组子集数据分别训练卷积神经网络模型;最后,采用多目标优化算法对N个卷积神经网络的预测结果进行集成.基于中国内蒙古地区的实际风电场数据开展算例验证,所提方法在均方根误差方面相比长短期记忆网络模型降低33.81%,相比基于卷积神经网络的组合预测模型降低24.08%,相比基于K-means聚类方法的预测降低14.05%. 展开更多
关键词 新能源预测 聚类 多目标优化 深度学习
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基于多源信息重构视图的不完备多视图自表示聚类 认领 引用 被引量：2
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作者 陈梅 王洁 +1 位作者 郭爱霞 王欢 《控制与决策》 EI CSCD 北大核心 2026年第3期765-776,共12页
针对现有不完备多视图聚类算法在恢复缺失数据时未保留原始结构,无法准确捕获多视图数据中局部结构和高阶信息等问题,提出基于多源信息重构视图的不完备多视图自表示聚类算法(MSRS).首先,利用多源信息重构反映原始数据结构特征的视图;然... 针对现有不完备多视图聚类算法在恢复缺失数据时未保留原始结构,无法准确捕获多视图数据中局部结构和高阶信息等问题,提出基于多源信息重构视图的不完备多视图自表示聚类算法(MSRS).首先,利用多源信息重构反映原始数据结构特征的视图;然后,基于重构的视图,采用一种结合稀疏约束与局部结构捕获的正则化方法,并引入加权张量Schat ten-p范数以动态控制不同奇异值的贡献,从而有效学习各视图的高质量自表示矩阵;最后,通过与9个先进的基线算法在3个真实和4个仿真不完备数据集上的实验结果表明,所提出算法在大多数情况下显著优于基线算法. 展开更多
关键词 多源信息重构 自表示学习 正则化约束 加权张量Schatten-p范数 不完备多视图聚类
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基于样本互补锚点图的缺失多视图聚类算法 认领 引用 被引量：1
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作者 刘小兰 徐宇鸿 《华南理工大学学报（自然科学版）》 EI CAS CSCD 北大核心 2026年第2期16-24,共9页
随着多视图数据在现实场景中得到广泛应用,如何处理缺失视图下的聚类问题已成为机器学习领域的重要挑战。传统锚点图聚类算法依赖完整实例构建锚点图,这导致其在高缺失率下因锚点不足难以表征数据结构,在低缺失率时又无法发挥锚点的优... 随着多视图数据在现实场景中得到广泛应用,如何处理缺失视图下的聚类问题已成为机器学习领域的重要挑战。传统锚点图聚类算法依赖完整实例构建锚点图,这导致其在高缺失率下因锚点不足难以表征数据结构,在低缺失率时又无法发挥锚点的优势。针对传统锚点图聚类算法中存在的锚点选择受限、权重分配僵化和计算复杂度高的问题,该文提出了一种基于样本互补锚点图的缺失多视图聚类算法(IMVC-SAC)。该算法首先设计跨视图锚点互补机制,通过在共有样本与视图特有样本中自适应选取锚点,以解决高缺失率下数据结构表征不足的问题;然后建立缺失模式感知的权重模型,依据样本的缺失模式与程度调整视图对相似矩阵的贡献度;最后利用双随机非负矩阵可分解特性,将谱聚类的时间复杂度从样本规模的立方阶复杂度优化至线性阶复杂度。在5个公开数据集上的实验结果表明,该算法的聚类性能优于目前主流算法,尤其在高缺失率下仍能保持较好的聚类效果,验证了其鲁棒性与有效性。 展开更多
关键词 缺失多视图聚类 锚点图 样本互补 相似矩阵融合 谱聚类
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本地差分隐私下基于聚类的两阶段多任务学习算法 认领 引用 被引量：2
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作者 方贤进 程俊 +3 位作者 张朋飞 方翔 陈家庆 王杰 《计算机工程与应用》 EI CSCD 北大核心 2026年第12期325-338,共14页
随着多任务学习在数据分析中的广泛应用,其隐私泄露风险日益凸显。传统方法依赖可信服务器且忽视噪声干扰,同时仅考虑任务相关性,导致隐私保护不足与模型性能下降。提出了一种满足本地差分隐私(local differential privacy,LDP)的基于K-... 随着多任务学习在数据分析中的广泛应用,其隐私泄露风险日益凸显。传统方法依赖可信服务器且忽视噪声干扰,同时仅考虑任务相关性,导致隐私保护不足与模型性能下降。提出了一种满足本地差分隐私(local differential privacy,LDP)的基于K-Means聚类的两阶段多任务学习算法(local differential privacy K-means-based twostage multi-task learning,KTMTL),旨在实现隐私保护与模型效用的协同优化。在第一阶段,通过改进K-means聚类算法,采用Huber距离替代欧氏距离,有效抑制因拉普拉斯噪声引入的离群点影响;在第二阶段,设计交互式多任务学习模型,联合建模任务间特征关联性与任务相关性,并利用梯度聚合优化模型参数。理论分析表明,KTMTL严格满足LDP且复杂度可控。在School、ADNI和合成数据集上的实验显示,KTMTL在相同隐私预算下,相较于DPMTRL和DP-DMTL,模型预测精度(AUC)提升10%~15%,归一化均方误差(nMSE)降低8%~12%,同时运行效率显著优于同类方法。KTMTL通过协同优化隐私保护与任务分组质量,为隐私敏感场景下的多任务学习提供了高效、鲁棒的解决方案。 展开更多
关键词 隐私保护 本地差分隐私 K-means聚类 多任务特征学习 多任务关系学习
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基于共识图学习的多任务多视图聚类 认领 引用
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作者 王丽娟 李雪燕 +4 位作者 尹明 郝志峰 蔡瑞初 陈薇 刘睿 《计算机工程》 CAS CSCD 北大核心 2026年第5期103-116,共14页
多视图聚类重点挖掘不同视图间的一致性信息,以提升多视图聚类性能。大多数现有的多视图聚类算法主要针对单任务多视图聚类,忽略了相关任务的相似性,使得多任务多视图聚类性能较差。而多任务聚类能够有效处理多个任务的相关性,实际中普... 多视图聚类重点挖掘不同视图间的一致性信息,以提升多视图聚类性能。大多数现有的多视图聚类算法主要针对单任务多视图聚类,忽略了相关任务的相似性,使得多任务多视图聚类性能较差。而多任务聚类能够有效处理多个任务的相关性,实际中普遍存在的聚类问题是多任务多视图数据聚类。为了更好地探究相关任务的关联性,同时从每个任务的多视图数据中获得更有效的一致性信息,提出一种基于共识图学习的多任务多视图聚类算法。该算法建立特定于视图的共享特征库,存储并迁移所有任务和所有视图共享的潜在信息,即每个任务在公共视图下共享的特征嵌入信息。当处理新任务时,一方面新任务的每个视图先通过同时优化相似图结构与对应的样本嵌入,以获得更准确的样本嵌入表示,另一方面引入协同聚类,实现共享特征库与新任务样本嵌入的知识迁移。这种方式利用特征嵌入的多样性信息来促进新任务各视图的一致性表达,同时根据新任务的样本信息更新共享特征库。在获得最优的样本嵌入表示后,将所有视图融合在一起,学习新任务的一个共识图。随后,采用交替方向策略优化模型,最终从共识图的拉普拉斯矩阵中引入秩约束以直接获得聚类结果。实验结果表明,与现有的6种先进算法相比,该算法在5个多任务多视图数据集上表现出更高的聚类性能和效率。 展开更多
关键词 多视图聚类 多任务学习 共识表示 图学习 协同聚类
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