BE2.R3: ARTIFICIAL INTELLIGENCE AND APPLICATIONS

Question Papers

July, 2004

January, 2004

July, 2004

Note:

1. Answer question 1 and any FOUR questions from 2 to 7. 2. Parts of the same question should be answered together

and in the same sequence.

Time: 3 Hours Total Marks:100

1. a. Explain the factors for the selection of Forward / Backward

reasoning to solve a problem.

b. Define "most general unifier" for two predicate calculus expressions.

c. Under what condition A* algorithm works as a random search. Explain.

d. How are fuzzy membership values different from probabilities?

e. Explain the reasons why sigmoid function is so important and popular as an activation function in neural networks.

f. How the machine learning is distinguished from general knowledge acquisition?

g. Describe regression in a backward production system.

(7x4)

2. a. Consider the following description in natural language:

If AIONICS employees do not belong to any union, then it is not true that every employee of AIONICS has to pay a

certain amount for union dues.

Express this statment in predicate calculus and convert it

into clause form. b. What is nonlinear planning and how it can be

implemented? Explain. c. Prove that modus ponens is sound for prepositional

calculus.

(8+6+4)

3. a. Consider the evidence e1 = single, e2 = high income, e3 =

young, supporting the hypothesis h1= high-risk investor or

h2 = low-risk investor, which are mutually exclusive and exhaustive. Assume that the domain expert estimates the

posterior probabilities as: P(h1) = 0.3, P(h2) = 0.7, P(e1/h1) = 0.6, P(e1/h2) = 0.3,

P(e2/h1) = 0.2, P(e2/h2) = 0.8, P(e3/h1) = 0.5, P(e3/h2) = 0.2.

Prove the following i. If all three evidences are present then the investor is

low-risk investor. ii. If e1 and e3 are present then the investor is high-

risk investor.

b. Explain the α, β cutoffs in minimax search. Give an example where it is useful.

(10+8)

4. a. Construct a semantic network for the following situation:

Mini is a robin; it lives in a nest, which is on a pine tree in Ms. Kavita's backyard. Robins are birds, they can fly and

they have wings. They are endangered species and they are protected by government regulations.

b. Create a simple frame based system composed of the objects employee, manager, technician and secretary.

Explain 'inheritance' in this context.

(9+9)

5. a. Describe the Hopfield model, the learning rule. Why do we

say lhallhe network performs an associative memory?

b. A neuron j receives inputs from two neurons whose activity levels are 0.6 and 0.5. The respective synaptic weights of j are -0.2 and 0.8. Calculate the output of tthe neuron if the

neuron uses the threshold function as the activation function. Assume the threshold 0.3.

(10+8)

6. a. Differentiate between RTN and ATN in the context of

Natural Language understanding. b. Give CD representation of the following sentence: c.

d. "ram was killed by excessive smoking."

e.

f. The game nim is played as follows: Two players alternatively removing one, two or three

pennies from a stack initially containing five pennies. The player who picks up the last penny loses. Show by drawing

the game graph that the player who has the second move

can always win.

(4+4+10)

7. a. Write a PROLOG program to determine if a list M is a sub

list of a list N. A list M is a sub list of N if the sequence of

elements in M is a contiguous subsequence of N. b. Show how means-ends analysis could be used to solve the

problem of getting from one place to anther. Assume that the available operators are walk, drive, take the bus, take

a cab and fly. c. Define operator PUSH using STRIPS like precondition, add

and delete conditions.

(6+6+6)

January, 2004

Note:

1. Answer question 1 and any FOUR questions from 2 to 7.

2. Parts of the same question should be answered together

and in the same sequence.

Time: 3 Hours Total Marks:100

1. a. In what context did Turing suggest his well-known test?

Explain the (Turing) test.

b. Find the probability of the event A when it is known that some event B occurred. From experiments, it has been

determined that P(B|A) =0.84, P(A) = 0.2 and P(B) = 0.34.

c. Discuss some characteristics that a control strategy should have, in order to be effective, in applying rules of a

production system. d. Why is it important that an expert system be able to

explain the why and how questions related to a problem solving session?

e. Let C and L be two fuzzy sets of COMFORTABLE and LARGE houses respectively. If the member grade of a given house

H being COMFORTABLE is 0.9 and being LARGE is 0.7, then what is the member grade of the house H being

i. LARGE and COMFORTABLE

ii. LARGE or COMFORTABLE f. What data structures are used for implementing linear

planning and non-linear planning? Justify your answers. ' Find. a most general unifier (m.g.u.) for

w={P(a,x,f(g(y))), P(z,f(z),f(u))}

(7 x 4)

2. a. Given below a game tree:

i. If the first player is a maximizing player then what

move should be chosen under mln-max procedure. ii. What nodes would not be examined using α-β

pruning procedure? b. Represent the following facts in predicate logic:

Some patient like all doctors No patient like any quack.

And show that no doctor is a quack using resolution.

3. ([5+7]+6) 4.

a. For a triangle ABC, it is given that the sum of the interior angles: LA + LB + LC =180 degrees. Show by resolution

theorem that the exterior angle is the sum of the opposite interior angles.

b. Describe the various conflict resolution strategies in Rule Based Expert Systems.

(12+6)

5. a. Let h' denote the estimate of h (the actual cost of getting

from the current node to a final state node). Explain in what way the efficiency of A* algorithm and reaching of a

goal state is affected if: i. h' always underestimates h;

ii. h' always overestimates h.

b. Using constraint satisfaction algorithm, solve the following cryptarithmetic: SEND

+MORE ---------

MONEY ---------

(8+10)

6. a. What are Perceptrons? Describe how the gradient descent

method is used in c.ontext of perceptrons. b. Define some good heuristic functions for each of the

following problems: i. Chess

ii. Travelling Salesman iii. Tic-Tac-Toe

(9+9)

7. a. Write a Prolog program to calculate gcd (greatest common

divisor) of two numbers. b. Write a Prolog program for obtaining a list after deleting all

occurrence of a particular element from a given list. c. Differentiate between 'green cut' and 'red cut' using

examples.

(6+6+6)

8. a. Develop a parse tree for the sentence 'Jack slept on the

table' using the following rules:

S -> NP VP

NP -> N

NP -> DET N

VP -> V PP

PP -> Prep NP

N -> jack | table

V -> slept

DET -> the

PREP -> on

b. Describe briefly the frame based knowiedge representation by explaining various types of inheritance present In

frame-based systems.