UNIVERSITY EXAMINATIONS: 2010/2011
SECOND YEAR EXAMINATION FOR THE DEGREE OF BACHELOR OF
SCIENCE IN INFORMATION TECHNOLOGY
BIT 2103: PRINCIPLES OF ARTIFICIAL INTELLIGENCE
DATE: AUGUST 2011 TIME: 2 HOURS
INSTRUCTIONS: Answer question ONE and any other TWO questions
Question One
a) Explain the meaning of the concept “knowledge representation”. [2 Marks]
b) Answer the following questions by indicating whether the statements are True (T) or False (F).
[5 Marks]
i) A rational intelligent agent acts in such a way as to minimize its expected value of performance
measure given the percept sequence to date.
ii)”Two primary school children, Dennis and Sarut are playing the Tic-tac-toe game. Dennis makes
the first move (starts the game).”The minimum number of moves Sarut could make is 2 for
Dennis to win the game.
iii) Depth-first search is often slower than Breadth-first search.
iv) Draughts and Scrabble are both deterministic games.
v)When playing games, the horizon effect can be solved by limiting the search depth.
c) Convert the following sentences into predicate logic [4 Marks]
i) ” a fruit is liked by everyone”
ii) ” Everything likes someone ”
d) A search tree is shown below where each circle represents a node corresponding to a state in the
search space. The estimated cost (i.e. h function) for finding a solution from a node is shown in its
circle. The two nodes with h = 0 are goal states and the other terminal nodes are dead-ends. (i.e.
states that can never reach a goal). Actual link costs are marked on the links between the nodes.
Thus the path cost (i.e. g function) of a node is equal to the sum of the link costs from the root to that
node.
i)Use depth-first search algorithm, to give the sequence of nodes expanded before a goal state is
reached. [2 Marks]
ii) What is the path cost. [2 Marks]
iii) Using the greedy search algorithm, give the sequence of nodes expanded before a goal state is
reached. What is the solution path and what is its path cost? [3 Marks]
e) Outline four differences between an agent and other software. [4 Marks]
f) Give three short-comings of using natural language for knowledge representation. [3 Marks]
g) use truth table to determine the following propositional calculus sentences (3 marks)
¬P ∧ Q ∨R ; where P and R have truth value F, and Q has truth value T
¬(P ∨ Q) ∧ (P ∨ R) ; where P, Q and R have truth value T
(Q ∨ R) ∧¬ R ∨ Q ; where R has truth value F and Q has truth value T [5 Marks]
h) . Define the term “Artificial Intelligence” [2 Marks]
Question Two
a) Describe the meaning of the concept “inference engine ” [2 Marks]
b) Discuss the elements of a search problem in the context of artificial intelligence. [5 Marks]
c) State and explain four characteristics of a good knowledge representation technique. [4 Marks]
d) Construct Semantic Net representations of the following sentence:
e) Explain the meaning of the following concepts [6 Marks].
i) Intrapersonal intelligence
ii) Backward chaining
iii)Forward chaining
f) Explain how artificial intelligence may be used in medicine and industry. Give one example
[3 Marks]
Question Three
a) Describe three methods of acquiring of knowledge. Give one example for each [6 Marks]
b) Explain the steps followed in the process of acquiring knowledge. [5 Marks]
c) Briefly explain two assumptions of knowledge representation. Give one example for each
assumption [4 Marks]
d) briefly explain any three challenges of knowledge engineering. [3 Marks]
e) distinguish between a ‘sensor’ and an ‘actuator’ in the context of intelligent agents technology
[ 2 Marks]
Question Four
a) Consider the MIN-MAX game tree given below. (To answer this question you will have to draw
two neat sketches of the tree on your answer sheet)
i).Fill in the utility function values at each node (the blank circles) in the MIN-MAX tree below, and
mark the first move path, from the root node (initial state) with a thick line. [2 Marks]
ii).Cross out the branches that are pruned by α-β pruning. How many nodes did you not have to visit
with α-β pruning (count the leaf nodes as well)? Show all intermediate values at each node as they get
updated. [4 Marks]
b) differentiate the following types of agent’s environments [4 Marks]
i).Accessible vs. in-accessible
ii). Episodic vs. non-episodic
c) State and explain two types of agents [2 Marks]
d) Describe the two principles of The Alpha-Beta values that are used during pruning in min max
algorithm [2 Marks]
e) You are given an expert system with several rules pertaining to the interpersonal skills of a job
applicant
R1: if the applicant answers questions in straight forward manner then she is easy to converse with
R2: If the applicant seems honest then she answers in straight forward manner.
R3: If the applicant has item on her resume that are found to be untrue then she does not have honest.
R4: If the applicant is able to arrange an appointment with the executive assistant then she is able to
strike up a conversation with the executive assistant.
R5: IF the applicant strikes up a conversation with the executive assistant and the applicant is easy to
converse with then she is amiable.
R6: If the applicant has adequate interpersonal skills. Then we will offer her the job.
Solve the following problems:
i) Assume that the applicant does not have any items or her resume that are found to be untrue and
that she is able to arrange an appointment with the executive assistant. Run a forward chain
analysis to find out whether we will offer her a job. [2 Marks]
ii)It is known that the applicant answers questions in straight forward manner. Run backward chain
analysis to find out whether we will offer a job to the applicant. [2 marks]
iii) We have just discovered that the applicant was able to arrange an appointment with the
executive assistant. It is also known that she is honest. Does she have interpersonal skills?
[2 marks]
Question Five
a) Explain the meaning of the term ‘knowledge base system’ [2 Marks]
b) Draw a well labelled structure of an expert system. [4 Marks]
c) Explain the function of each part of an expert system drawn in (b) [7 Marks]
d) Describe four benefits of including an explanation facility in an expert system [4 Marks]
e) Briefly explain any Three applications of knowledge based systems [3 Marks]
