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1.
模糊关联产生的大量候选数据项集使得在大型数据库中数据处理效率很低;提出基于本体的模糊关联规则挖掘系统;通过利用领域本体提高模糊关联规则挖掘效果,改变了挖掘算法,提出新规则.实验表明得到的新规则更有意义.  相似文献   

2.
针对模糊属性事务数据库提取模糊关联规则的问题,采用模糊概念格与模糊关联规则相结合的方法,实现格节点与属性项集的对应关系,提出模糊关联规则格理论,在渐进式建格算法基础上对格节点相应修改,给出了适用于动态数据库的模糊关联规则格的构建思想.利用模糊关联规则格挖掘关联规则,与采用Apriori算法计算频繁项目集获取规则相比较,容易获得用户感兴趣的关联规则,同时减少冗余规则的生成,使挖掘算法得到优化.  相似文献   

3.
基于数据库约简的关联规则挖掘算法   总被引:7,自引:0,他引:7  
通过对Apriori算法挖掘过程进行分析,提出了一种基于数据库约简的关联规则挖掘算法.该算法利用每趟挖掘中一些非频繁项集的超集、并集,逐步约简事务数据库中的事务,提高了关联规则的挖掘效率.在这些非频繁项集的基础上建立了数据库约简的定理和推论,并在Apriori算法的基础上设计了ApioriNEW算法.经过对算法进行分析和实验,算法ApioriNEW的挖掘效率比较高.一般情况下,平均可将挖掘效率提高约30%.ApioriNEW算法特别适合大型数据库的关联规则挖掘,已应用在网络故障诊断专家系统的知识获取中.  相似文献   

4.
Web日志挖掘是Web数据挖掘中非常重要的一个研究领域和研究方向,首先介绍了Web日志挖掘的过程,然后介绍了关联规则及关联规则算法——FP-growth算法,最后将关联规则中的FP-growth算法应用在网上书店系统中,实现对客户数据的关联规则挖掘。  相似文献   

5.
快速关联规则挖掘算法   总被引:1,自引:0,他引:1  
刘景春 《佳木斯大学学报》2004,22(2):151-156,177
提出了一种新颖的关联规则挖掘算法QAIS,与经典两阶段式关联规则挖掘算法不同的是,它只需扫描一遍事务数据库,不需要生成候选集,并且可以方便的应用在增量式关联规则挖掘算法中,该算法经合成数据验证是有效的.同时针对关联规则生成过程中出现大量冗余规则的问题,还讨论了冗余关联规则去除的问题.  相似文献   

6.
介绍了模糊关联规则挖掘算法的基本思想及实现步骤,提出了模糊关联规则的并行挖掘算法.并行挖掘算法采用并行的模糊c-均值算法将数量型属性划分成若干个模糊集,并借助模糊集软化属性的划分边界.用改进布尔型关联规则的并行挖掘算法来发现频繁模糊属性集.最后由多个处理器并行地产生满足最小模糊信任度的模糊关联规则.在分布式互连的PC/工作站环境下进行性能分析,结果表明并行的挖掘算法具有好的可扩展性、规模增长性和加速比性能.  相似文献   

7.
分析了关联规则挖掘的各种算法,详尽分析和探讨了一种用于挖掘关联规则的矩阵算法并给出了矩阵算法实现过程.矩阵算法扫描数据库一次,然后生成事务矩阵,在矩阵上进行相关的数据挖掘操作.当数据库规模较大时,矩阵算法能够显著提高关联规则挖掘的效率.  相似文献   

8.
王磊 《甘肃科技》2006,22(3):119-121
该文介绍了模糊关联规则挖掘算法的基本思想及实现步骤,提出了一种对原始数据先进行模糊聚类,再提取规则的基于模糊集和粗糙集技术的关联规则挖掘策略。  相似文献   

9.
关联规则挖掘Apriori算法的改进及其应用研究   总被引:1,自引:0,他引:1  
在分析经典关联规则挖掘算法的基础上.提出了一种改进的Aprioff关联规则算法.并进行该算法的UCI机嚣学习数据库性能分析和设计电子病历关联规则挖掘应用系统.结果表明该算法在运行速度和挖掘性能上都是高效的.  相似文献   

10.
应用模糊关联规则分析农业信息中的数值型数据,为了解决数值型数据的模糊集转换问题,定义了基于SOM算法的模糊集梯形隶属函数自适应转换方法,设计了挖掘系统的功能及体系结构.基于FDMA算法,开发了农业信息模糊关联规则挖掘系统.结合农业生产实际,对农业信息数据进行预处理,使用开发的系统实施了数据挖掘,并对挖掘结果进行了分析,结果表明:农业信息模糊关联规则挖掘系统具有一定的应用价值.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

20.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

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