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1.
约束关联规则是数据挖掘的一个主要方向,可以根据用户给定的约束条件针对性的挖掘.目前大多数的研究都集中在约束频繁项集挖掘方面,很少进行序列模式的约束关联挖掘.本文把序列模式和约束进行结合,提出一种基于约束的序列模式关联规则挖掘算法.它同时处理两类约束:反单调性约束和单调性约束.可以根据约束条件挖掘数据间的因果关联关系.通过实验验证,该算法在运行效率上达到了较好效果.  相似文献   

2.
针对复杂系统产生的时间序列,研究其局部关联特征比研究系统全局特征模型具有明显的优势.为研究时间序列内部或局部形态的关联特征,首先借助FCM来软化时间序列属性论域的划分边界,然后,采用改进的布尔型属性关联规则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.提出了基于FCM聚类的时间序列模糊关联规则的并行挖掘算法,并通过实验验证了算法的有效性.  相似文献   

3.
多维时序模糊关联规则在高炉炉温预报中的应用   总被引:1,自引:0,他引:1  
根据目前高炉炉温预报推理规则都是由高炉专家根据经验制定的情况,提出了一种新的规则生成方法——数据挖掘获取高炉炉温预报关联规则.针对现有挖掘算法的不足,提出了一种改进的多维时间序列模糊关联规则挖掘算法,该算法基于时间子序列和子序列间隔的双重模糊化,避免了挖掘结果"时间边界锐化"的问题.该算法应用于武钢的1#高炉,挖掘效果良好.  相似文献   

4.
一种基于关联模式的完全决策规则的提取方法   总被引:2,自引:1,他引:1  
针对基于粗糙集理论提取完全的决策规则是NP难问题,提出一种获取统计意义下的完全的简化规则的算法.该算法结合关联规则挖掘方法和粗糙集方法的优点,从决策表中提取出具有一定支持度和可信度阈值的决策规则,具有实际的应用意义.通过实例验证了算法的有效性.  相似文献   

5.
针对数据流并行聚集问题,提出了一种不同于关系数据和时间序列数据处理的并行聚集方法.为解决已经划分出的数据流元组无法再现的特点,提出能够感知数据流变化的采样算法对数据流采样.利用近似等深柱状图技术描述采样数据的分布特征,平均分配数据流量.使用时间聚集森林结构计算时间窗聚集.通过验证采样个数对并行聚集的影响,数据分布对近似划分向量算法性能的影响,测试数据流量与并行聚集加速比的关系,证明本算法能够高效地计算数据流聚集查询.  相似文献   

6.
传统的偏好推理使用权衡增强的条件偏好网络(Tradeoff-Enhanced Conditional Preference Networks,TCP-nets)进行用户的偏好推理,不仅能高效地表示对元组的定性偏好关系并优化用户偏好结果,还能描述每个属性之间的偏好关系,其主要聚焦于关系元组中的单个属性的偏好.但把对条件偏好查询的技术推广到数据流的条件提取却是一个挑战,面临的技术困难主要是对数据流中序列的提取,对提取的序列进行占优查找等.首先,针对偏好数据流,提出一种时间条件查询语言Stream Pref来处理数据流;其次,在Stream Pref中加入时间索引来推理和规范数据流提取序列的时间条件偏好,提出提取对象序列算法、占优对象及占优序列查找算法和数据流序列间占优对比的算法;最后,在数据集上分析验证提出的算法的有效性.实验结果证明,提出的算法与min Top-k,Partition和Incpartition算法相比,得到的结果更准确.  相似文献   

7.
负关联规则的研究   总被引:15,自引:0,他引:15  
传统的关联规则是A(=)┐B的形式,将这种形式加以扩展,讨论了A(=)┐B, ┐A(=)B,┐A(=)┐B三种形式,给出了一种负关联规则中支持度与置信度简单有效的计算方法.讨论了同时研究正、负关联规则后出现的矛盾规则问题,提出了用相关性解决这些问题的方法和一种挖掘频繁项集中正、负关联规则的算法,进行了算法的验证实验.实验结果表明,该算法能检测并删除相互矛盾的规则.  相似文献   

8.
提出一种新的镜头边界枪测算法.该算法充分利用视频帧中的颜色信息,提取每帧的矢量特征值.形成视频帧特征值序列.针对该特征值序列的滑动窗口引入散度算法和非参数密度估计法.根据特定视频帧矢量值在滑动窗口中两个不同概率密度值的相异性特征.得到该帧在两种不同概率分布下的散度值;同时,提出一种新的基于统计学的自动阈值获取方案,能很好地检测出切变和渐变.对多种类型的视频序列进行测试的实验结果表明,检测结果达到了95.3%的查全率和95.2%的查准率.  相似文献   

9.
在全参考或者部分参考的视频质量评价算法中,由于视频序列在传输过程中总会存在丢帧、跳帧、停滞等现象,因此在视频质量评价之前进行的帧对齐处理是非常重要的步骤.提出了一种新的帧对齐算法,该方法在国际电信联盟(ITU)的ITU-T J.244和J.247的基础上,对源视频和劣化视频序列进行预处理和相关特征参数的提取,并采用类似滑动窗口的原理对二者进行相似度的运算,根据运算结果可判断是否达到帧对齐.结果表明,该方法可以明显甄别出视频序列相应帧的对齐情况,算法简单、实时性较好,具有一定的实用价值.  相似文献   

10.
关联规则的挖掘往往会产生大量的关联规则,"规则爆炸"的问题会使用户很难得到自己所需要的重要信息.极大布尔关联规则集因其包含的规则数量少且不丢失规则信息的优点提高了用户分析关联规则结果的效率,且节省了规则存储空间.在分析频繁闭项集、频繁基项集和极大布尔关联规则性质的基础上提出了一种挖掘极大布尔关联规则的算法,利用此算法可以得到极大布尔关联规则集,还通过实例验证了算法的正确性.  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.
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   

15.
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   

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.
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   

19.
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   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

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