trí tuệ nhân tạo,cao hoàng trụ,dhbkhcm

trí tuệ nhân tạo,cao hoàng trụ,dhbkhcm TRƯỜNG ĐẠI HỌC BÁCH KHOA TP HCM Khoa Khoa học & Kỹ thuật Máy tính 1 ARTIFICIAL INTELLIGENCE Tutorial 2 Questions PROBLEMS & SEARCH Question 1 State Space Search[.]

TRƯỜNG ĐẠI HỌC BÁCH KHOA TP.HCM Khoa Khoa học & Kỹ thuật Máy tính

ARTIFICIAL INTELLIGENCE

Tutorial 2 Questions PROBLEMS & SEARCH Question 1 State Space Search

For each of the following problems, specify (i) a representation for a state; (ii) the start and goal states and (iii) set of rules, each of which is followed by an example

Example problem: The water-jug problem in the lecture notes

State representation: a pair (x,y) where x and y are respectively the amounts of water

in 4-litre and 3-litre jugs

Start state: (0,0)

Goal state: (2,n) 0<=n<=3

Set of rules:

- Fill up the first jug: (2,2)  (4,2)

- Fill up the second jug: (2,2)  (2,3)

- Empty the first jug: (2,2)  (0,2)

- Empty the second jug: (2,2)  (2,0)

- Fill up the first jug by the water in the second one: (2,3)  (4,1)

- Fill up the second jug by the water in the first one: (2,1)  (0,3)

- Empty the first jug to the second one: (1,1)  (0,2)

- Empty the second jug to the first one: (2,1)  (3,0)

a) The 8-puzzle problem: The 8-puzzle is a small board game for a single player; it

consists of 8 square tiles numbered 1 through 8 and one blank space on a 3 x 3 board, as depicted in left board in Figure 1 Moves of the puzzle are made by sliding an adjacent tile into the position occupied by the blank space, which has the effect of exchanging the positions of the tile and blank space Only tiles that are horizontally or vertically adjacent (not diagonally adjacent) may be moved into the blank space The object is to reach the configuration in the right board of Figure 1

TRƯỜNG ĐẠI HỌC BÁCH KHOA TP.HCM Khoa Khoa học & Kỹ thuật Máy tính

Figure 1 – An instance of the 8-puzzle problem

Give all states that can be generated from the left board in Figure 2

b) The 8-queens problem: The eight queens puzzle is the problem of putting eight

chess queens on an 8×8 chessboard such that none of them is able to capture any other using the standard chess queen's moves Figure 3 depicts one solution

Figure 2 – An example solution for the 8-queens problem c) Touring problems: Visit every city in Figure 3 at least once, starting, and ending

in Bucharest

TRƯỜNG ĐẠI HỌC BÁCH KHOA TP.HCM Khoa Khoa học & Kỹ thuật Máy tính

Figure 3: A road map of Romania

d) Robot navigation problem: Robot navigation means its ability to determine its

own position in its frame of reference and then to plan a path towards some goal location In order to navigate in its environment, the robot or any another mobility device requires representation i.e a map of the environment and the ability to

interpret that representation

In this problem, we will deal with a situation in which the robot has to go from start to goal position in the room full of obstacles In this situation, some works that we have to do One of them is path finding, and how can the robot know which way to go This problem can be mapped into problem of finding path from point S to point G and this path must not cut over polygons between S and G (figure 4)

TRƯỜNG ĐẠI HỌC BÁCH KHOA TP.HCM Khoa Khoa học & Kỹ thuật Máy tính

Figure 4: Finding path from point S to point G Question 2

Analyze each of four problems in Question 1 with respect to the seven problem

characteristics discussed in Chapter 2

Question 3 Uninformed search - DFS and BFS

After formalizing problems (defined state space, initial states, goal states and rules),

we have to apply search strategies to go from initial state to goal state The search

graph will have start node as the initial state The edges are actions and the nodes

correspond to states in the state space of the problem The search process finds

possible action sequences starting at the start node of search graph to goal state (end

node)

In the problem of question 1c,find a solution using Depth-First-Search and

Breadth-First-Search Assume that when performing the BFS traversal, the cities will be considered in counter-alphabetical order when in the same level