UGC NET CSE | November 2017 | Part 3 | Question: 71

Question

Consider a single perceptron with sign activation function. The perceptron is represented by weight vector $\begin{bmatrix} 0.4 & -0.3 & 0.1 \end{bmatrix}^t$ and a bias $\theta=0$. If the input vector to the perceptron is $X=\begin{bmatrix} 0.2 & 0.6 & 0.5 \end{bmatrix}$ then the output of the perceptron is

• A. $1$
• B. $0$
• C. $-0.05$
• D. $-1$

Answer 1

Ans: (3) -0.05

Explanation: Here it is given input vector X=[0.2 0.6 0.5] and weight vector W=[0.4 −0.3 0.1]^T 

The output of the perceptron will be the summation of X and W represented as,

$\sum_{i}^{}$Xi Wi                                    (i=1,2,3 because there are 3 values of X and W)

[0.2 0.6 0.5]*[0.4 −0.3 0.1]=[0.2*0.4     0.6*(-0.3)     0.5*0.1]=[0.08-0.18+0.05] = -0.05

 

 

Comments

-1 will be answer because of definition of sign function.update it .

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https://i.stack.imgur.com/NPA2j.jpg

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why not +1
Pls explain

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P=1, if P>0

P=-1, if P<0

P=0, if P=0

since value of P is -0.05(<0), so output is -1

Where P represents perceptron and P=$\sum w_i\cdot x_i$

Answer 2

Consider a single perceptron with sign activation function. The perceptron is represented by
weight vector [0.4 −0.3 0.1] t and a bias θ=0. If the input vector to the perceptron is
X=[0.2 0.6 0.5] then the output of the perceptron is

A. 1       B. 0         C. −0.05       D. −1


ANS:  ​​​​​​​OPTION C
Output = AX + B where A = weight, X= input, B = bias
Output = [0.4 −0.3 0.1]^t   [0.2 0.6 0.5] + [0 0 0]
Output = 0.4 * 0.2 + -0.3*0.6 + 0.1*0.5
Output = 0.08 - 0.18 + 0.05
Output = 0.13 - 0.18
Output = -0.05
 

Comments

in sign activation function output is either +1 or -1  .  here -0.05 is input which is less than 0  so output will be -1

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Yes. Thanks