【单选题】The process of manipulating one or more independent variables and measuring their effect on one or more dependent variables while controlling for the extraneous variables is called a(n、________.
E.
manipulation measurement
【单选题】两个有限长序列x1[n]=[1 2 3 4]和x2[n]=[1 0 2 0],若x1[n]与x2[n]循环卷积后的结果序列为x[n],则x[n]为:
【简答题】已知两个长为N的有限长序列x 1 (n)和x 2 (n)互为倒序关系,即 x 1 (n)={x(0),x(1),…,x(N-2),x(N-1)}, x 2 (n)={x(N-1),x(N-2),…,x(1),x(0)) 它们的离散傅里叶变换分别是X 1 (z)和X 2 (z)。从下列4个等式中选择正确答案。 A.X 2 (k)= X 1 (-k) B.X 2 (k)=X 1 (N-1--k)...
【简答题】两个有限长序列x(n)和y(n)的零值区间为 x(n)=0, n<0.8≤n Y(n)=0, n<0.20≤n 对每个序列作20点DFT,即 X(k)=DFT[x(n)], k=0,1,…,19 Y(k)=DFT[y(n)],k=0,1,…,19 如果 F(k)=X(k)·Y(k) k=0,1,…,19 f(n)=IDFT[F(k)],k=0,1,…,19 试问在哪些点上f(n)=x(n)...
【判断题】使用同一概念的不同词语搜索的结果完全相同。
【单选题】Variables that measure the effect of the independent variables on the test units are called ________.
A.
interdependent variables
【判断题】With experimental designs, it is possible to control for some of the extraneous variables.
【判断题】The process of manipulating one or more independent variables and measuring their effect on one or more dependent variables while controlling for the extraneous variables is called an experiment.
【判断题】Experiments call for selecting matched groups of subjects, subjecting them to different treatments, controlling extraneous variables, and checking whether observed response differences are statistical...