下述中()方法只适用于鼠笼式异步电动机。 A.变极调速 B.变阻调速 C.变频调速

题型:单项选择题

问题:

下述中()方法只适用于鼠笼式异步电动机。

A.变极调速

B.变阻调速

C.变频调速

D.电磁调速

考点:中级维修电工中级维修电工题库
题型:单项选择题

新生儿腰椎穿刺的部位应当是()

A.第1腰椎以下即可

B.第2、3腰椎间隙

C.第3、4腰椎间隙

D.第4、5腰椎间隙

E.第5腰椎

题型:单项选择题

对于ⅣA族元素,下列叙述中不正确的是

A.该族元素的金属性逐渐增强

B.它们的原子最外层电子数都是4,次外层电子数都8

C.CO2和SiO2都是酸性氧化物,在一定条件下都能和氧化钙反应

D.该族元素的原子半径逐渐增大

题型:单项选择题

Data mining is an (66) research field in database and artificial intelligence. In this paper, the data mining techniques are introduced broadly including its producing background, its application and its classification. The principal techniques used in the data mining are surveyed also, which include rule induction, decision (67) , artificial (68) network, genetic algorithm, fuzzy technique, rough set and visualization technique. Association rule mining, classification rule mining, outlier mining and clustering method are discussed in detail. The research achievements in association rule, the shortcomings of association rule measure standards and its (69) , the evaluation methods of classification rules are presented. Existing outlier mining approaches are introduced which include outlier mining approach based on statistics, distance-based outlier mining approach, data detection method for deviation, rule-based outlier mining approach and multi-strategy method. Finally, the applications of data mining to science research, financial investment, market, insurance, manufacturing industry and communication network management are introduced. The application (70) of data mining are described.

(70)处填()。

A.course

B.disadvantage

C.prosperity

D.prospects

题型:单项选择题

一个1:N联系可转换为一个独立的关系模式,关系的码为

A.N端实体的码

B.实体的码

C.各实体码的组合

D.每个实体的码

题型:单项选择题

挂柳防浪时,应选用()的柳树头或柳枝。

A.细小顺直

B.枝叶茂密

C.枝杈少

D.叶稀少

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