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基于优化FP⁃Growth算法的滑坡频繁因素组合挖掘
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作者 李佳颖 郝彬超 +4 位作者 王卫东 王智超 曹禄来 韩征 朱崇政 《防灾减灾工程学报》 北大核心 2025年第3期532-541,共10页
滑坡影响因素复杂多样,挖掘滑坡的频繁因素组合能宏观快速地初步判识滑坡易发区域。以四川省凉山彝族自治州内586处滑坡灾害为样本数据,从地质条件、水文条件、地形条件、气象条件和人类工程活动五个方面收集12个滑坡影响因素,基于卡方... 滑坡影响因素复杂多样,挖掘滑坡的频繁因素组合能宏观快速地初步判识滑坡易发区域。以四川省凉山彝族自治州内586处滑坡灾害为样本数据,从地质条件、水文条件、地形条件、气象条件和人类工程活动五个方面收集12个滑坡影响因素,基于卡方检验剔除与滑坡灾害弱相关的影响因素,耦合分析滑坡区域与影响因素区划,针对大数据挖掘算法仅能以历史滑坡次数等离散型变量为挖掘依据的局限性,引入特征参数优化频繁模式树(FPGrowth)算法,使其能以历史滑坡面积和历史滑坡密度等连续型变量为挖掘依据,挖掘滑坡频繁二级因素组合,利用卡方检验与频率比检验挖掘结果准确性。结果表明:基于历史滑坡密度的优化关联规则算法能更好地挖掘滑坡频繁二级因素组合,其中,“高程<1769 m、地表起伏度62~140 m”的区域滑坡最频繁,需要对滑坡灾害重点关注与防治。针对原始关联规则算法仅能以滑坡次数为挖掘依据的局限,优化算法以考虑滑坡范围的影响,深入研究多种影响因素对滑坡的综合作用,为滑坡灾害的快速判识与防灾减灾提供参考。 展开更多
关键词 大数据挖掘技术 优化关联规则算法 FP-growth算法 滑坡影响因素 频繁组合挖掘
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Managing cotton canopy architecture for machine picking cotton via high plant density and plant growth retardants 被引量:1
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作者 LAKSHMANAN Sankar SOMASUNDARAM Selvaraj +4 位作者 SHRI RANGASAMI Silambiah ANANTHARAJU Pokkharu VIJAYALAKSHMI Dhashnamurthi RAGAVAN Thiruvengadam DHAMODHARAN Paramasivam 《Journal of Cotton Research》 2025年第1期102-114,共13页
Machine picking in cotton is an emerging practice in India,to solve the problems of labour shortages and production costs increasing.Cotton production has been declining in recent years;however,the high density planti... Machine picking in cotton is an emerging practice in India,to solve the problems of labour shortages and production costs increasing.Cotton production has been declining in recent years;however,the high density planting system(HDPS)offers a viable method to enhance productivity by increasing plant populations per unit area,optimizing resource utilization,and facilitating machine picking.Cotton is an indeterminate plant that produce excessive vegeta-tive growth in favorable soil fertility and moisture conditions,which posing challenges for efficient machine picking.To address this issue,the application of plant growth retardants(PGRs)is essential for controlling canopy architecture.PGRs reduce internode elongation,promote regulated branching,and increase plant compactness,making cotton plants better suited for machine picking.PGRs application also optimizes photosynthates distribution between veg-etative and reproductive growth,resulting in higher yields and improved fibre quality.The integration of HDPS and PGRs applications results in an optimal plant architecture for improving machine picking efficiency.However,the success of this integration is determined by some factors,including cotton variety,environmental conditions,and geographical variations.These approaches not only address yield stagnation and labour shortages but also help to establish more effective and sustainable cotton farming practices,resulting in higher cotton productivity. 展开更多
关键词 COTTON High density planting system Plant growth retardant Canopy management Defoliators Machine picking Yield improvement
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Mechanism and application of seed-induced goethite crystal growth for iron removal from rich-zinc solution 被引量:1
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作者 ZHU Qiang YANG Jian-guang +5 位作者 NAN Tian-xiang ZENG Wei-zhi TANG Shi-yang LIU Jiang ZHANG Yan TANG Chao-bo 《Journal of Central South University》 2025年第3期837-852,共16页
The goethite residue generated from zinc hydrometallurgy is classified as hazardous solid waste,produced in large quantities,and results in significant zinc loss.The study was conducted on removing iron from FeSO_(4)-... The goethite residue generated from zinc hydrometallurgy is classified as hazardous solid waste,produced in large quantities,and results in significant zinc loss.The study was conducted on removing iron from FeSO_(4)-ZnSO_(4) solution,employing seed-induced nucleation methods.Analysis of the iron removal rate,residue structure,morphology,and elemental composition involved ICP,XRD,FT-IR,and SEM.The existing state of zinc was investigated by combining step-by-step dissolution using hydrochloric acid.Concurrently,iron removal tests were extended to industrial solutions to assess the influence of seeds and solution pH on zinc loss and residue yield.The results revealed that seed addition increased the iron removal rate by 3%,elevated the residual iron content by 6.39%,and mitigated zinc loss by 29.55%in the simulated solution.Seed-induced nucleation prevented excessive nuclei formation,fostering crystal stable growth and high crystallinity.In addition,the zinc content of surface adsorption and crystal internal embedding in the residue was determined,and the zinc distribution on the surface was dense.In contrast,the total amount of zinc within the crystal was higher.The test results in the industrial solution demonstrated that the introduction of seeds expanded the pH range for goethite formation and growth,and the zinc loss per ton of iron removed was reduced by 50.91 kg(34.12%)and the iron residue reduced by 0.17 t(8.72%). 展开更多
关键词 iron removal crystal growth homogeneous and heterogeneous nucleation goethite process zinc hydrometallurgy
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An Algorithm for Cloud-based Web Service Combination Optimization Through Plant Growth Simulation
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作者 Li Qiang Qin Huawei +1 位作者 Qiao Bingqin Wu Ruifang 《系统仿真学报》 北大核心 2025年第2期462-473,共12页
In order to improve the efficiency of cloud-based web services,an improved plant growth simulation algorithm scheduling model.This model first used mathematical methods to describe the relationships between cloud-base... In order to improve the efficiency of cloud-based web services,an improved plant growth simulation algorithm scheduling model.This model first used mathematical methods to describe the relationships between cloud-based web services and the constraints of system resources.Then,a light-induced plant growth simulation algorithm was established.The performance of the algorithm was compared through several plant types,and the best plant model was selected as the setting for the system.Experimental results show that when the number of test cloud-based web services reaches 2048,the model being 2.14 times faster than PSO,2.8 times faster than the ant colony algorithm,2.9 times faster than the bee colony algorithm,and a remarkable 8.38 times faster than the genetic algorithm. 展开更多
关键词 cloud-based service scheduling algorithm resource constraint load optimization cloud computing plant growth simulation algorithm
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On the Relative Growth Rate of the Digits in Sylvester Continued Fraction Expansions
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作者 LV Meiying RAO Guilin 《应用数学》 北大核心 2025年第2期468-476,共9页
For the Sylvester continued fraction expansions of real numbers,FAN et al.(2007)proved that,for almost all real numbers,the nth partial quotient grows exponentially with respect to the product of the first n-1 partial... For the Sylvester continued fraction expansions of real numbers,FAN et al.(2007)proved that,for almost all real numbers,the nth partial quotient grows exponentially with respect to the product of the first n-1 partial quotients.In this paper,we establish the Hausdorff dimension of the exceptional set where the growth rate is a general function. 展开更多
关键词 Sylvester continued fraction expansions growth rate Hausdorff dimension
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Residual effects of butisanstar and clopyralid herbicides on Gossypium hirsutum L.growth:insights from a pot experiment
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作者 SOLTANI TOULAROUD Ali Ashraf GOLCHIN Ahmad ROUHI‑KELARLOU Tohid 《Journal of Cotton Research》 2025年第3期389-401,共13页
Background The intensive use of herbicides in agriculture raises concerns about their residual impacts on non-target crops such as cotton(Gossypium hirsutum L.),which is often rotated with cereals,sugar beet,and canol... Background The intensive use of herbicides in agriculture raises concerns about their residual impacts on non-target crops such as cotton(Gossypium hirsutum L.),which is often rotated with cereals,sugar beet,and canola.Butisanstar(BUT)and clopyralid(CLO)are widely used for broadleaf weed control in these rotations.However,how residual herbicide activity influences cotton growth and development is not well understood.This study evaluated these residual effects by measuring multiple growth parameters in a greenhouse.Cotton was grown for 40 days in soil incubated for 90 days with herbicide treatments arranged in a factorial design(type:BUT,CLO,and their combination;dose:0,1/2,1,2,and 5×recommended field dose[RFD]).Results Herbicide residues reduced cotton growth in a dose-dependent manner,with greater inhibition at higher doses.The combined BUT+CLO treatment produced the strongest negative effects,followed by CLO and then BUT alone.Compared with controls,seedling emergence declined by 12%–83%,root length by 12%–87%,plant height by 10%–84%,and chlorophyll index by 12%–80%across treatments from 1/2×RFD BUT to 5×RFD BUT+CLO.Root and shoot biomass also decreased significantly.Under the 5×RFD combined treatment,shoot N,P,and K concentrations dropped by 48%,78%,and 70%,respectively,relative to the control.Conclusions Even low levels of residual BUT and CLO impair cotton growth.To mitigate these effects,it should avoid planting cotton on recently treated soils,leave sufficient intervals between herbicide application and cotton planting,and apply soil amendments to boost microbial degradation.These measures are essential for sustaining soil health and cotton productivity. 展开更多
关键词 COTTON Herbicide residues growth traits Nutrient concentrations Seedling emergence
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Use of supervised and unsupervised approaches to make zonal application maps for variable-rate application of crop growth regulators in commercial cotton fields
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作者 ANDREA Maria C.da S. OLIVEIRA Cristiano F.de +7 位作者 MOTA Fabrícia C.M. SANTOS Rafael C.dos RODRIGUES JUNIOR Edilson F. BIANCHI Lucas M. OLIVEIRA Rodrigo S.de GOUVEIA Caio M.de BARBOSA Victor G.S. BISPO E SILVA Marco A. 《Journal of Cotton Research》 2025年第1期1-20,共20页
Background Zonal application maps are designed to represent field variability using key variables that can be translated into tailored management practices.For cotton,zonal maps for crop growth regulator(CGR)applicati... Background Zonal application maps are designed to represent field variability using key variables that can be translated into tailored management practices.For cotton,zonal maps for crop growth regulator(CGR)applications under variable-rate(VR)strategies are commonly based exclusively on vegetation indices(VIs)variability.However,VIs often saturate in dense crop vegetation areas,limiting their effectiveness in distinguishing variability in crop growth.This study aimed to compare unsupervised framework(UF)and supervised framework(SUF)approaches for generat-ing zonal application maps for CGR under VR conditions.During 2022-2023 agricultural seasons,an UF was employed to generate zonal maps based on locally collected field data on plant height of cotton,satellite imagery,soil texture,and phenology data.Subsequently,a SUF(based on historical data between 2020-2021 to 2022-2023 agricultural seasons)was developed to predict plant height using remote sensing and phenology data,aiming to replicate same zonal maps but without relying on direct field measurements of plant height.Both approaches were tested in three fields and on two different dates per field.Results The predictive model for plant height of SUF performed well,as indicated by the model metrics.However,when comparing zonal application maps for specific field-date combinations,the predicted plant height exhibited lower variability compared with field measurements.This led to variable compatibility between SUF maps,which utilized the model predictions,and the UF maps,which were based on the real field data.Fields characterized by much pronounced soil texture variability yielded the highest compatibility between the zonal application maps produced by both SUF and UF approaches.This was predominantly due to the greater consistency in estimating plant development patterns within these heterogeneous field environments.While VR application approach can facilitate product savings during the application operation,other key factors must be considered.These include the availability of specialized machinery required for this type of applications,as well as the inherent operational costs associated with applying a single CGR product which differs from the typical uniform rate applications that often integrate multi-ple inputs.Conclusion Predictive modeling shows promise for assisting in the creation of zonal application maps for VR of CGR applications.However,the degree of agreement with the actual variability in crop growth found in the field should be evaluated on a field-by-field basis.The SUF approach,which is based on plant heigh prediction,demonstrated potential for supporting the development of zonal application maps for VR of CGR applications.However,the degree to which this approach aligns itself with the actual variability in crop growth observed in the field may vary,necessi-tating field-by-field evaluation. 展开更多
关键词 Cotton Site-specific management Crop growth regulator Unsupervised framework Supervised framework Zonal application maps
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Tomato Growth Height Prediction Method by Phenotypic Feature Extraction Using Multi-modal Data
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作者 GONG Yu WANG Ling +3 位作者 ZHAO Rongqiang YOU Haibo ZHOU Mo LIU Jie 《智慧农业(中英文)》 2025年第1期97-110,共14页
[Objective]Accurate prediction of tomato growth height is crucial for optimizing production environments in smart farming.However,current prediction methods predominantly rely on empirical,mechanistic,or learning-base... [Objective]Accurate prediction of tomato growth height is crucial for optimizing production environments in smart farming.However,current prediction methods predominantly rely on empirical,mechanistic,or learning-based models that utilize either images data or environmental data.These methods fail to fully leverage multi-modal data to capture the diverse aspects of plant growth comprehensively.[Methods]To address this limitation,a two-stage phenotypic feature extraction(PFE)model based on deep learning algorithm of recurrent neural network(RNN)and long short-term memory(LSTM)was developed.The model integrated environment and plant information to provide a holistic understanding of the growth process,emploied phenotypic and temporal feature extractors to comprehensively capture both types of features,enabled a deeper understanding of the interaction between tomato plants and their environment,ultimately leading to highly accurate predictions of growth height.[Results and Discussions]The experimental results showed the model's ef‐fectiveness:When predicting the next two days based on the past five days,the PFE-based RNN and LSTM models achieved mean absolute percentage error(MAPE)of 0.81%and 0.40%,respectively,which were significantly lower than the 8.00%MAPE of the large language model(LLM)and 6.72%MAPE of the Transformer-based model.In longer-term predictions,the 10-day prediction for 4 days ahead and the 30-day prediction for 12 days ahead,the PFE-RNN model continued to outperform the other two baseline models,with MAPE of 2.66%and 14.05%,respectively.[Conclusions]The proposed method,which leverages phenotypic-temporal collaboration,shows great potential for intelligent,data-driven management of tomato cultivation,making it a promising approach for enhancing the efficiency and precision of smart tomato planting management. 展开更多
关键词 tomato growth prediction deep learning phenotypic feature extraction multi-modal data recurrent neural net‐work long short-term memory large language model
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Corrosion-assisted fatigue crack growth behaviour of AA 7075-T651 friction stir welded joints:Influence of extended seawater exposure on microstructure and fracture characteristics
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作者 Karthick Ganesan S.R.Koteswara Rao +1 位作者 T.Srinivasa Rao V.Rohit 《Defence Technology(防务技术)》 2025年第9期80-96,共17页
This study investigates the corrosion-assisted fatigue crack growth rate(FCGR)of 16 mm thick AA 7075-T651 friction stir welded(FSW)joints.Compact tension(CT)specimens were extracted from both the base material and FSW... This study investigates the corrosion-assisted fatigue crack growth rate(FCGR)of 16 mm thick AA 7075-T651 friction stir welded(FSW)joints.Compact tension(CT)specimens were extracted from both the base material and FSW joints to evaluate FCGR under varying corrosion exposure durations(0,7,30,60,and 90 days)at a constant stress ratio of 0.5.Microstructural analysis of the welds was conducted using optical and transmission electron microscopy(TEM).Results indicate that the critical stress intensity factor range(ΔK_(cr))of FSW joints is lower than that of the base material,primarily due to precipitate dissolution in the weld zone during the FSW process,as confirmed by TEM analysis.The fatigue life of FSW joints was significantly lower than that of the base material,but with prolonged exposure to seawater corrosion,the gap in fatigue life narrowed.Specimens exposed to seawater for more than 60days exhibited minimal differences in fatigue life between the base material and the FSW joints.This was attributed to the higher corrosion rate of the base material compared to the weld nugget,resulting in the formation of deeper pits that facilitated crack initiation and accelerated fatigue failure.The findings conclude that extended corrosion exposure leads to similar fatigue life and crack growth behaviour in both the base material and FSW joints.SEM and EDX analysis of AA7075-T651 revealed corrosion pits and rust products in initiation zones,ductile striations in growth regions,and secondary cracks with micro voids in fracture zones.FSW joints exhibited ultra-fine grains,smooth ductile fracture in initiation and growth regions,and brittle fracture in the fracture zones under both corroded and uncorroded conditions. 展开更多
关键词 Fatigue crack growth Pre-corrosion exposure Paris constants AA7075-T651 alloy Friction stir weld joints Precipitate-free zones(PFZs)
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Role of bisphosphonates in osteoporosis caused by adult growth hormone deficiency 被引量:2
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作者 CHENG Zhiling LI Jie +1 位作者 CHEN Zhongpei REN Wei 《中南大学学报(医学版)》 CAS CSCD 北大核心 2024年第6期839-847,共9页
In recent years,growth hormone and insulin-like growth factors have become key regulators of bone metabolism and remodeling,crucial for maintaining healthy bone mass throughout life.Studies have shown that adult growt... In recent years,growth hormone and insulin-like growth factors have become key regulators of bone metabolism and remodeling,crucial for maintaining healthy bone mass throughout life.Studies have shown that adult growth hormone deficiency leads to alterations in bone remodeling,significantly affecting bone microarchitecture and increasing fracture risk.Although recombinant human growth hormone replacement therapy can mitigate these adverse effects,improving bone density,and reduce fracture risk,its effectiveness in treating osteoporosis,especially in adults with established growth hormone deficiency,seems limited.Bisphosphonates inhibit bone resorption by targeting farnesyl pyrophosphate synthase in osteoclasts,and clinical trials have confirmed their efficacy in improving osteoporosis.Therefore,for adult growth hormone deficiency patients with osteoporosis,the use of bisphosphonates alongside growth hormone replacement therapy is recommended. 展开更多
关键词 growth hormone adult growth hormone deficiency OSTEOPOROSIS BISPHOSPHONATES insulin-like growth factor 1 SKELETON
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Insulin-like growth factor-binding protein-3 inhibits IGF-1-induced proliferation of human hepatocellular carcinoma cells
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作者 Yang MA Chen-chen HAN +2 位作者 Yi-fan LI Yang WANG Wei WEI 《中国药理学与毒理学杂志》 CAS CSCD 北大核心 2017年第10期966-966,共1页
OBJECTIVE Basic fibroblast growth factor(b FGF)and platelet-derived growth factor(PDGF)produced by hepatocellular carcinoma(HCC)cells are responsible for the cell growth.Accumulating evidence shows that insulin-like g... OBJECTIVE Basic fibroblast growth factor(b FGF)and platelet-derived growth factor(PDGF)produced by hepatocellular carcinoma(HCC)cells are responsible for the cell growth.Accumulating evidence shows that insulin-like growth factor-binding protein-3(IGFBP-3)suppresses HCC cell proliferation in both IGF-dependent and independent manners.The present study is to investigate whether treatment with exogenous IGFBP-3 inhibits bF GF and PDGF production and the cell proliferation of HCC cells.METHODS Cell Counting Kit 8 assay were designed to detect HCC cell proliferation,transcription factor early growth response-1(EGR1)involving in IGFBP-3 regulation of b FGF and PDGF were detected by RT-PCR and Western blot assays.Western blot assay was adopted to detect the IGFBP-3 regulating insulin-like growth factor 1 receptor(IGF-1R)signaling pathway.RESULTS The present study demonstrates that IGFBP-3 suppressed IGF-1-induced b FGF and PDGF expression while it does not affect their expression in the absence of IGF-1.To delineate the underlying mechanism,Western-blot and RT-PCR assays confirmed that the transcription factor early growth response protein 1(EGR1)is involved in IGFBP-3 regulation of b FGF and PDGF.IGFBP-3 inhibition of type 1 insulin-like growth factor receptor(IGF1R),ERK and AKT activation is IGF-1-dependent.Furthermore,transient transfection with constitutively activated AKT or MEK partially blocks the IGFBP-3 inhibition of EGR1,b FGF and PDGF expression.CONCLUSION In conclusion,these findings suggest that IGFBP-3suppresses transcription of EGR1 and its target genes b FGF and PDGF through inhibiting IGF-1-dependent ERK and AKT activation.It demonstrates the importance of IGFBP-3 in the regulation of HCC cell proliferation,suggesting that IGFBP-3 could be a target for the treatment of HCC. 展开更多
关键词 insulin-like growth factor-binding protein-3 early growth response-1 insulin-like growth factor 1 receptor cell proliferation
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基于FP-Growth数据挖掘的直流串联故障电弧特征提取及检测方法
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作者 杨晓华 费正源 +3 位作者 代盛国 刘家欣 陈思磊 李兴文 《广东电力》 北大核心 2025年第3期104-112,共9页
为解决传统时频分析方法难以有效提取多种电极材料下的故障电弧特征,导致故障电弧检测装置拒动而引发火灾的问题,提出了基于频繁模式增长(FP-Growth)数据挖掘的直流故障电弧检测算法,实现多种电极材料下的特征有效提取。基于改进粒子群... 为解决传统时频分析方法难以有效提取多种电极材料下的故障电弧特征,导致故障电弧检测装置拒动而引发火灾的问题,提出了基于频繁模式增长(FP-Growth)数据挖掘的直流故障电弧检测算法,实现多种电极材料下的特征有效提取。基于改进粒子群算法对检测算法的准确率、检测时间和内存大小进行协同优化,实现在硬件资源受限条件下故障电弧检测算法最优参数的选取。经过测试验证表明该方法能够快速、有效地检测不同电极材料下的直流串联故障电弧,为基于材料差异的故障电弧特征提取及检测方法的硬件实现提供参考。 展开更多
关键词 故障电弧 频繁模式增长 协同优化 改进粒子群 硬件实现 机器学习
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Fast Growth of Crystals from Aqueous Solutions
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作者 V.A.Kuinotsou 《人工晶体学报》 CSCD 1991年第3期208-208,共1页
The increasing of the growth rate of the crystals from aqueous solutions(simultaneously keeping a good quality of the crystals)remains the important problem.A comparison of fast grown and low grown KDP crystals shows,... The increasing of the growth rate of the crystals from aqueous solutions(simultaneously keeping a good quality of the crystals)remains the important problem.A comparison of fast grown and low grown KDP crystals shows,that some properties of the former are often better than low grown materials. 展开更多
关键词 CRYSTALS kdp crystals fast growth crystal quality aqueous solutions increasing growth rate growth rate KDP crystals
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一种基于FP-Growth的频繁项目集并行挖掘算法 被引量:44
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作者 章志刚 吉根林 《计算机工程与应用》 CSCD 2014年第2期103-106,共4页
FP-Growth算法是基于FP树挖掘频繁项目集的经典算法,为提高FP-Growth算法挖掘大规模数据频繁项目集的效率,提出了一种基于FP-Growth的频繁项目集并行挖掘算法FPPM。该算法基于Map/Reduce并行模型,在每个计算节点上首先构造局部频繁模式... FP-Growth算法是基于FP树挖掘频繁项目集的经典算法,为提高FP-Growth算法挖掘大规模数据频繁项目集的效率,提出了一种基于FP-Growth的频繁项目集并行挖掘算法FPPM。该算法基于Map/Reduce并行模型,在每个计算节点上首先构造局部频繁模式树,并对之进行挖掘得到局部频繁项目集,然后合并局部频繁项目集以得到全局频繁项集,由于此时得到的结果并不完备,所以对合并后未达到最小支持度阈值的项目集,重新计算其支持数。介绍了FPPM算法的设计思想,测试了其性能。实验结果表明FPPM算法具有较好的可扩展性。 展开更多
关键词 频繁项目集 并行挖掘 FP growth MAP REDUCE
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负载均衡的FP-growth并行算法研究 被引量:10
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作者 曾志勇 杨呈智 陶冶 《计算机工程与应用》 CSCD 北大核心 2010年第4期125-126,229,共3页
针对在大数据量频繁模式挖掘的时候,有效地利用空闲的计算资源,提出一种基于FP-growth算法的并行算法。该算法有效地将FP-growth主要的计算部分合理地分配到各个计算节点上,各个节点独立完成挖掘后返回结果,从而缩短总计算时间。实验证... 针对在大数据量频繁模式挖掘的时候,有效地利用空闲的计算资源,提出一种基于FP-growth算法的并行算法。该算法有效地将FP-growth主要的计算部分合理地分配到各个计算节点上,各个节点独立完成挖掘后返回结果,从而缩短总计算时间。实验证明,该算法可以完整高效地挖掘频繁模式,并且实现均衡负载。 展开更多
关键词 数据挖掘 并行算法 FP—growth 频繁模式
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基于布尔矩阵和MapReduce的FP-Growth算法 被引量:23
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作者 陈兴蜀 张帅 +1 位作者 童浩 崔晓靖 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 2014年第1期135-141,共7页
关联规则挖掘是数据挖掘的一个重要组成部分.为提高关联规则的挖掘效率,提出了一种基于布尔矩阵和MapReduce的FP-Growth算法(BPFP),分析了算法的时间和空间复杂度.该算法使用Hadoop框架和布尔矩阵以减少对事务数据的扫描次数,利用两次Ma... 关联规则挖掘是数据挖掘的一个重要组成部分.为提高关联规则的挖掘效率,提出了一种基于布尔矩阵和MapReduce的FP-Growth算法(BPFP),分析了算法的时间和空间复杂度.该算法使用Hadoop框架和布尔矩阵以减少对事务数据的扫描次数,利用两次MapReduce来实现频繁项集的挖掘.在多个数据集上的实验结果表明,与原FP-Growth算法相比,BPFP算法具有更高的执行效率、更好的加速比. 展开更多
关键词 数据挖掘 关联规则 布尔矩阵 MAPREDUCE FP-growth算法
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基于负载均衡和冗余剪枝的并行FP-Growth算法 被引量:8
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作者 刘祥哲 刘培玉 +2 位作者 任敏 伊静 高钊 《数据采集与处理》 CSCD 北大核心 2016年第1期223-230,共8页
针对现有的并行FP-Growth算法在数据并行分组时存在数据冗余和负载不均的问题,提出了基于负载估算和冗余剪枝的优化算法。首先,在采用高频策略分组时,引入节点任务估算方法,把每个分组中最大模式树的最长路径和支持度作为该分组的估计值... 针对现有的并行FP-Growth算法在数据并行分组时存在数据冗余和负载不均的问题,提出了基于负载估算和冗余剪枝的优化算法。首先,在采用高频策略分组时,引入节点任务估算方法,把每个分组中最大模式树的最长路径和支持度作为该分组的估计值,将估计值远大于其他节点的分组进行分割,平均到其他分组中,并且对不同分组中重复的列表元素进行截断,去除冗余数据。实验表明,本文提出的算法能够有效防止并行化的数据倾斜,减少数据冗余,在时间和空间复杂度上要低于以前的并行化FP-Growth算法。 展开更多
关键词 关联规则 MAPREDUCE 冗余剪枝 FP-growth算法
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基于FP-growth算法的高校群体性突发事件关联规则分析 被引量:14
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作者 姬浩 苏兵 吕美 《中国安全科学学报》 CAS CSCD 北大核心 2012年第12期144-151,共8页
为有效预防高校群体性突发事件,借助数据挖掘关联规则挖掘理论,在分析高校突发事件关键诱发因素基础上,构建基于FP-growth算法的高校群体性突发事件关联规则挖掘模型。并将模型应用于事务数据库数据的分析中,研究关键诱发因素间关联关系... 为有效预防高校群体性突发事件,借助数据挖掘关联规则挖掘理论,在分析高校突发事件关键诱发因素基础上,构建基于FP-growth算法的高校群体性突发事件关联规则挖掘模型。并将模型应用于事务数据库数据的分析中,研究关键诱发因素间关联关系,实现强关联规则输出。研究结果表明,多数高校群体性突发事件的发生与日期没有必然联系;内部管理因素、内外部突发事件、内部突发事件、政治因素是诱发高校群体性突发事件的主要因素,且外部因素导致的群体性突发事件影响力远远超过内部因素的影响力;当突发事件发生后,应急处置的有效性是决定突发事件影响力的重要因素。 展开更多
关键词 高校安全 群体性突发事件 数据挖掘 FP-growth算法 关联规则
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基于FP-growth关联规则的图书馆数据快速挖掘算法研究 被引量:15
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作者 文芳 黄慧玲 +1 位作者 李腾达 王佳斌 《重庆理工大学学报(自然科学)》 CAS 北大核心 2020年第6期189-194,共6页
作为一种模糊关联规则挖掘算法,FP-growth算法在执行效率上明显优于Apriori算法。但是由于模糊属性的不足和空间复杂度较大,导致FP-growth算法在处理大型事务数据库,例如图书馆数据库时,无法实现有效的多层关联规则挖掘。因此,提出一种... 作为一种模糊关联规则挖掘算法,FP-growth算法在执行效率上明显优于Apriori算法。但是由于模糊属性的不足和空间复杂度较大,导致FP-growth算法在处理大型事务数据库,例如图书馆数据库时,无法实现有效的多层关联规则挖掘。因此,提出一种改进的FP-growth关联规则算法,能够快速向读者进行个性化图书推荐。首先,该算法把大型图书事务数据库根据首项的事务,划分为若干子数据库,并构建相应的子FP-tree结构;然后,采用实时过滤掉层次树中不是频繁项的父项来缩小扫描空间。实验结果表明:相比Apriori算法和标准FP-growth算法,提出的改进FP-growth关联规则算法在运行效率方面有明显提升,为图书的推荐工作提供了科学依据。 展开更多
关键词 数据挖掘 图书馆 模糊关联规则 APRIORI FP-growth 运行效率
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INTERGROWTH-21^(st)标准评价胎儿宫内生长受限的临床价值 被引量:10
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作者 朱晨 任芸芸 吴江南 《复旦学报(医学版)》 CAS CSCD 北大核心 2017年第3期307-311,325,共6页
目的探讨INTERGROWTH-21^(st)标准评价胎儿宫内生长受限的应用价值。方法本研究为前瞻性队列研究。收集2015年3月至2016年3月在复旦大学附属妇产科医院建卡,进行常规产前检查并入院分娩的单胎妊娠孕妇。所有入选病例孕28周之后入组,每4... 目的探讨INTERGROWTH-21^(st)标准评价胎儿宫内生长受限的应用价值。方法本研究为前瞻性队列研究。收集2015年3月至2016年3月在复旦大学附属妇产科医院建卡,进行常规产前检查并入院分娩的单胎妊娠孕妇。所有入选病例孕28周之后入组,每4周做一次产前超声生长测量,直至分娩前。胎儿生长径线以INTERGROWTH-21^(st)标准计算Z-score值。分娩后随访新生儿体重等相关信息。应用Logistic回归方程建立预测公式。最后将新公式与Hadlock法预测IUGR的准确性进行对比。结果共收集符合入组条件的孕妇834例。排除失访143例后,得到对照组565例和IUGR组126例。新预测公式的敏感性、特异性、阳性预测值、阴性预测值、假阳性率、假阴性率分别为:88.9%、85.4%、57.7%、97.2%、14.6%、11.1%。Hadlock法预测的敏感性、特异性、阳性预测值、阴性预测值、假阳性率、假阴性率分别为:81.7%、82.7%、51.2%、95.3%、17.3%、18.3%。结论以INTERGROWTH-21^(st)标准计算Z-score建立新公式预测胎儿宫内生长受限的方法,与传统的Hadlock预测法相比,改善了产前诊断的敏感性和特异度,减少了假阳性和假阴性的病例,全面提高了超声预测胎儿宫内生长受限的准确性。 展开更多
关键词 INTERgrowth-21st Z-SCORE 胎儿宫内生长受限 超声生长测量 晚孕期
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