朴素贝叶斯分类算法及其应用研究

介绍了朴素贝叶斯分类算法的原理,研究了基于朴素贝叶斯算法的数据分类。实际应用表明了朴素贝叶斯算法是一种有效的分类算法。     

朴素贝叶斯分类算法及基应用研究

介绍了朴素贝叶斯分类算法的原理,研究了基于朴素贝叶斯算法的数据分类.实际应用表明了朴素贝叶斯算法是一种有效的分类算法.     

基于稀疏贝叶斯学习的煤岩图像识别方法

为了探索煤岩图像识别的新方法,提出了基于稀疏贝叶斯学习(SBL)的煤岩图像识别方法。该学习模型是在贝叶斯框架下,有着更强大的数据挖掘能力和稀疏能力,并通过该模型下的回归和分类算法成功的解决了煤岩图像识别的实际问题。实验证明,不论是运行速度还是识别率方面均取得不错的效果。     

基于校园一卡通的数据挖掘与应用

我国是一个重视教育的国家,九年制义务教育使得每一位适龄学生都能进入学校读书。但是到了高等教育阶段,并不能像之前一样免费接受教育,这使得好多家庭贫困学生的求学过程变得困难,如何将助学金发放给真正贫困且品学兼优的学生这是一个非常重要的事情。校园一卡通的应用是数字校园的重要一环,一卡通刷卡记录里面包含有学生在学校期间各方面的信息:食堂消费记录、图书借阅情况、超市消费记录、学业成绩考试情况等。本文尝试将数据挖掘技术应用在校园一卡通的数据分析中,采用贝叶斯算法及决策树算法,从一卡通消费行为习惯、学习成绩、图书借阅情况等方面综合考虑,寻找出贫困学生,为学校相关部门提供参考意见,使得助学金能更多、更准确地资助品学兼优、刻苦上进但家庭贫困的学生,帮助他们更好地完成学业。本文首先介绍了进行数据挖掘分析的总体流程,接着着重分析了本论文仿真实验时采用的两种挖掘分析算法,最后基于Rapidminerstudio平台对整个挖掘分析过程进行验证,并评估两种算法模型的效果。     

基于三次遍历的快速关联规则数据挖掘算法

挖掘频繁项集是许多数据挖掘任务中的关键问题,也是关联规则挖掘算法的核心,提高频繁项集的生成效率一直是近几年数据挖掘领域研究的热点之一。在分析当前Apriori算法及其改进算法的基础上,本文介绍了一种基于三次遍历的快速关联规则挖掘算法,该算法在运算速度上明显好于Apriori算法。最后,对该算法和Apriori算法在一些方面进行了比较。     

数据挖掘中的聚类算法的综述

聚类是数据挖掘中用来发现数据分布和隐含模式的一项重要技术。阐述了聚类算法基本原理,总结了聚类算法的研究现状,按照聚类算法的分类,分析比较了三种典型聚类的性能差异和各自存在的优点及问题,并结合应用需求指出了其今后的发展趋势。     

大数据分析挖掘技术及决策探讨

在当前各行各业数据分析中一般会用到挖掘技术,从海量数据中将有价值的数据挖掘出来,计算机研究中主要结合遗传算法进行应用,保证数据挖掘的科学性与合理性,在技术上保障了我国社会经济的发展。在大数据背景下,我们应该关注数据分析、数据挖掘和数据的利用率,保证决策制定的有效性。本文将简述大数据分析挖掘技术及决策的作用,并介绍了具体应用案例。     

大数据在互联网学习中的应用与研究

本文分析了大数据应用于互联网学习的方式,并对其应用流程进行了探讨。在互联网学习中,有效应用大数据,能够从海量的资源中获得有价值的学习内容,而且还能有针对性地为学习者提供服务。互联网学习平台通过互联网整合不同的资源,对不同类型的知识加以分类梳理,借助数据挖掘、机器学习等算法进行挖掘,从中获取有价值的内容并推送给学习者。     

基于短语的网络文本挖掘分类的再探讨

网络文本分类的进一步改进除了算法方面,应该还立足于影响网络文本分类最底层、网络文本分类是数据挖掘的重要课题,根据对具有主题的大量网络文本的分析,论述了网络文本分类的较详细的情况。     

浅谈数据挖掘技术

本文的开篇首先引入了什么是数据挖掘，之后提出了数据挖掘与数据仓库关系。在此基础上，对数据挖掘的功能即关联分析做了简要描述，最后指出应用数据挖掘技术的注意事项。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。