Computer Science - An Overview

Glenn Brookshear, Dennis Brylow

Chapter 11

Artificial Intelligence - all with Video Answers

Educators

Chapter Questions

Problem 1

As demonstrated in Section $11.2,$ humans might use a question for a purpose other than asking. Another example is "Do you know that your tire is flat?" which is used to inform rather than to ask. Give examples of questions used to reassure, to warn, and to criticize.

Samuel Goyette

Samuel Goyette

Numerade Educator

Problem 2

Analyze a soda dispensing machine as an agent. What are its sensors? What are its actuators? What level of response (reflex, knowledge-based, goal-based) does it exhibit?

David Collins

Numerade Educator

Problem 3

Identify each of the following responses as being reflex, knowledge based, or goal based. Justify your answers.
a. $A$ computer program translating text from German to English
b. $A$ thermostat turning on the furnace when the temperature in a house drops below the current setting
c. $A$ pilot landing a plane safely on a runway

YH

Yazeed Hamami

Numerade Educator

Problem 4

If a researcher uses computer models for studying the memorization capabilities of the human mind, do the programs developed for the machine necessarily memorize to the best of the machine's abilities? Explain.

Samuel Goyette

Numerade Educator

Problem 5

Give some examples of declarative knowledge. Give some examples of procedural knowledge.

Samuel Goyette

Numerade Educator

Problem 6

In the context of object-oriented programming, what parts of an object are used to store declarative knowledge? What parts are used to store procedural knowledge?

Samuel Goyette

Numerade Educator

Problem 7

Which of the following activities do you expect to be performance oriented and which are simulation oriented?
a. The design of an automated shuttle system (often used at airports between terminals)
b. The design of a model predicting the path of a hurricane
c. The design of a Web search database used to derive and maintain indices for documents stored on the World Wide Web
d. The design of a model of a nation's economy for testing theories
e. The design of a program for monitoring a patient's vital signs

Patina Herring

Numerade Educator

Problem 8

Today, some telephone calls to businesses are handled by automated answering systems that use speech and voice recognition to converse with the caller. Do these systems pass the Turing test? Explain your answer.

Jennifer Stoner

Jennifer Stoner

Numerade Educator

Problem 9

Identify a small set of geometric properties that can be used to distinguish between the symbols $\mathrm{F}, \mathrm{E}, \mathrm{L},$ and $\mathrm{T}$

Samuel Goyette

Numerade Educator

Problem 10

Describe the similarities between the technique of identifying characteristics by comparing them to templates and the error correcting codes discussed in Chapter 1

Harsh Gadhiya

Numerade Educator

Problem 11

Describe two interpretations of the following line drawing based on whether the "corner" marked A is convex or concave:

Samuel Goyette

Numerade Educator

Problem 12

Compare the roles of the prepositional phrases in the following two sentences (which differ by only one word). How could a machine be programmed to make such distinctions?
The pigpen was built by the barn. The pigpen was built by the farmer.

Billy Huggins

Numerade Educator

Problem 13

How do the results of parsing the following two sentences differ? How do the results of semantic analysis differ?

An awesome sunset was seen by Andrea.
Andrea saw an awesome sunset.

Mayank Tripathi

Mayank Tripathi

Numerade Educator

Problem 14

How do the results of parsing the following two sentences differ? How do the results of semantic analysis differ?

If $X<10$ then subtract 1 from $X$ else add 1 from $X$
If $X>10$ then add 1 to $X$ else subtract 1 from $X$

Zach Steedman

Numerade Educator

Problem 15

In the text we briefly discussed the problems of understanding natural languages as opposed to formal programming languages. As an example of the complexities involved in the case of natural languages, identify situations in which the question "Do you know what time it is?" has different meanings.

Samuel Goyette

Numerade Educator

Problem 16

Changes in the context of a sentence can change the significance of the sentence as well as its meaning. In the context of Figure $11.3,$ how would the significance of the sentence "Mary hit John" change if the birth dates were in the late 2000 s? What if one were
in the 1980 s and the other in the late 2000 s?

Harshita Goel

Numerade Educator

Problem 17

Draw a semantic net representing the information in the following paragraph. Donna threw the ball to Jack, who hit it into center field. The center fielder tried to catch it, but it bounced off the wall instead.

James Kiss

Numerade Educator

Problem 18

Sometimes the ability to answer a question depends as much on knowing the limits of knowledge as it does on the facts themselves. For example, suppose databases A and B both contain a complete list of employees who belong to the company's health insurance program, but only database A is aware that the list is complete. What could database A conclude about a member who was not on its list that database B could not?

Jennifer Stoner

Jennifer Stoner

Numerade Educator

Problem 19

Give an example in which the closed-world assumption leads to a contradiction.

Jennifer Stoner

Jennifer Stoner

Numerade Educator

Problem 20

Give two examples where the closed-world assumption is commonly used.

Jennifer Stoner

Jennifer Stoner

Numerade Educator

Problem 21

In the context of a production system, what is the difference between a state graph and a search tree?

Niamat Khuda

Numerade Educator

Problem 22

Analyze the task of solving the Rubik's cube in terms of a production system. (What are the states, the productions, and so on?)

Rishi Kavikondala

Rishi Kavikondala

Numerade Educator

Problem 23

a. Suppose a search tree is a binary tree and reaching the goal requires eight productions. What is the largest number of nodes that could be in the tree when the goal state is reached if the tree is constructed with a breadth-first manner?
b. Explain how the total number of nodes considered during the search could be reduced by conducting two searches at the same time-one beginning at the initial state while the other searches backward from
the goal-until the two meet. (Assume that the search tree recording the states found in the backward search is also a binary tree and that both searches progress at the same rate.)

Chris Trentman

Numerade Educator

Problem 24

In the text we mentioned that a production system is often used as a technique for drawing conclusions from known facts. The states of the system are the facts known to be true at each stage of the reasoning process, and the productions are the rules of logic for manipulating the known facts. Identify some rules of logic that allow the conclusion "John is tall" to be obtained from the facts that "John is a basketball player," "Basketball players are not short," and "John is either short or tall."

Ian Shi

Numerade Educator

Problem 25

The following tree represents possible moves in a competitive game, showing that player X currently has a choice between move A and move B. Following the move of player $X,$ player $Y$ is allowed to select a move, and then player $X$ is allowed to select the last move of the game. The leaf nodes of the tree are labeled $\mathrm{W}, \mathrm{L},$ or $\mathrm{T}$, depending on whether that ending represents a win, loss, or tie for player X. Should player X select move A or move B? Why? How does selecting a "production" in a competitive atmosphere differ from a one-person game such as the eight-puzzle?

Nick Johnson

Numerade Educator

Problem 26

Analyze the game of checkers as a production system and describe a heuristic that could be used to determine which of two states is closer to the goal. How would the control system in this setting differ from that of a one-person game such as the eight-puzzle?

Tyler Moulton

Numerade Educator

Problem 27

By considering the manipulation rules of algebra as productions, problems involving the simplification of algebraic expressions can be solved in the context of a production system. Identify a set of algebraic productions that allow the equation $3 /(2 x-1)=6 /(3 x+1)$ to be reduced to the form $x=3 .$ What are some general rules (that is, heuristic rules) used when performing such algebraic simplifications?

AG

Ankit Gupta

Numerade Educator

Problem 28

Draw the search tree that is generated by a breadth-first search in an attempt to solve the eight-puzzle from the following start state without using the assistance of any heuristic information.

Nick Johnson

Numerade Educator

Problem 29

Draw the search tree that is generated by the best-fit algorithm of Figure 11.10 in an attempt to solve the eight-puzzle from the start state in problem 28 if the number of tiles out of place is used as a heuristic.

Chris Trentman

Numerade Educator

Problem 30

Draw the search tree that is generated by the best-fit algorithm of Figure 11.10 in an attempt to solve the eight-puzzle from the following start state, assuming the heuristic used is the same as that developed in Section 11.3

James Kiss

Numerade Educator

Problem 31

When solving the eight-puzzle, why would the number of tiles out of place not be as good a heuristic as the one used in Section $11.3 ?$

Ayan Basu

Numerade Educator

Problem 32

What is the distinction between the technique of deciding which half of the list to consider when performing a binary search (Section 5.5) and deciding which branch to pursue when performing a heuristic search?

Bryan Lynn

Numerade Educator

Problem 33

Note that if a state in the state graph of a production system has an extremely low heuristic value in comparison to the other states and if there is a production from that state to itself, the algorithm in Figure 11.10 can get caught in the loop of considering that state over and over again. Show that if the cost of executing any production in the system is at least one, then by computing the projected cost to be the sum of the heuristic value plus the cost of reaching the state along the path being traversed, this endless looping process will be avoided.

Breanna Ollech

Numerade Educator

Problem 34

What heuristic do you use when searching for a route between two cities on a large road map?
Draw to four levels the search tree produced

WZ

Wen Zheng

Numerade Educator

Problem 35

Draw to four levels the search tree produced by the best-fit algorithm of Figure 11.10 in finding the route from Trent to Wildwood. Each node in the search tree will be a city on the map. Begin with a node for Trent. When expanding a node, add only the cities that are directly connected to the city being expanded. Record in each node the straight-line distance to Wildwood and use this as the heuristic value. Does the best-fit algorithm have a defect in its processing? If so, what correction is needed?

WZ

Wen Zheng

Numerade Educator

Problem 36

The $A^{*}$ algorithm modifies the best-fit algorithm in two significant ways. First, it records the actual cost to reach a state. In the case of a
route on a map, the actual cost is the distance traveled. Second, when selecting a node to expand, it chooses the node whose sum of the actual cost plus heuristic value is the smallest. Draw the search tree of problem 35 that would result from these two modifications. Record in each node the distance traveled to the city, the heuristic value to reach the goal, and their sum. What is the found path from Dearborn to Wildwood?

WZ

Wen Zheng

Numerade Educator

Problem 37

List two properties that a heuristic should have if it is to be useful in a production system.

Ameer Said

Numerade Educator

Problem 38

Suppose you have two buckets. One has a capacity of exactly three liters; the other has a capacity of five liters. You can pour water from one bucket to another, empty a bucket, or fill a bucket at any time. Your problem is to place exactly four liters of water in the fiveliter bucket. Describe how this problem could be framed as a production system.

James Chok

Numerade Educator

Problem 39

Suppose your job is to supervise the loading of two trucks, each of which can carry at most fourteen tons. The cargo is a variety of crates whose total weight is twenty-eight tons but whose individual weights vary from crate to crate. The weight of each crate is marked on its side. What heuristic would you use for dividing the crates between the two trucks?

Victor Salazar

Numerade Educator

Problem 40

Which of the following are examples of meta-reasoning?
a. He has been gone long so he must have gone far.
b. since I usually make the wrong decision and the last two decisions I made were cor-
rect, I will reverse my next decision.
c. I am getting tired so I am probably not thinking clearly.
d. I am getting tired so I think I will take a
nap.

Emily Himsel

Numerade Educator

Problem 41

Describe how a human's ability to solve the frame problem helps the human find lost articles.

Vishal Sharma

Numerade Educator

Problem 42

a. In what sense is learning by imitation similar to learning by supervised training?
b. In what sense is learning by imitation different from learning by supervised training?

Deborah Taylor

Numerade Educator

Problem 43

The following diagram represents an artificial neural network for an associative memory as discussed in Section $11.5 .$ What pattern does it associate with any pattern in which only two neurons that are separated by a single neuron are excited? What will happen if the network is initialized with all its neurons inhibited?

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 44

The following diagram represents an artificial neural network for an associative memory as discussed in Section $11.5 .$ What stable configuration does it associate with any initial pattern in which at least three of the neurons on the perimeter are excited and the center neuron is inhibited? What would happen if it were given an initial pattern in which only two neurons that are opposite each other on the perimeter were excited?

Tanner Fonjweng

Tanner Fonjweng

Numerade Educator

Problem 45

Design an artificial neural network for an associative memory (as discussed in Section 11.5 ) consisting of a rectangular array of neurons that tries to move toward stable patterns in which a single vertical column of neurons is excited.

Joanna Quigley

Numerade Educator

Problem 46

Adjust the weights and threshold values in the artificial neural network in Figure 11.18 so that its output is 1 when both inputs are the same (both 0 or both 1) and 0 when the inputs are different (one being 0 while the other is 1 ).

Breanna Ollech

Numerade Educator

Problem 47

Draw a diagram similar to Figure 11.5 representing the process of simplifying the algebraic expression $7 x+3=3 x-5$ to the expression $x=-2$

Amy Jiang

Numerade Educator

Problem 48

Expand your answer to the previous problem to show other paths that a control system might pursue when attempting to solve the problem.

Linda Winkler

Numerade Educator

Problem 49

Draw a diagram similar to Figure 11.5 representing the reasoning process involved when concluding that "Polly can fly" from the initial facts "Polly is a parrot," "A parrot is a bird," and "All birds can fly."

James Kiss

Numerade Educator

Problem 50

In contrast to the statement in the preceding problem, some birds, such as an ostrich or a robin with a broken wing, cannot fly. However, it would not seem reasonable to construct a deductive reasoning system in which all the exceptions to the statement "All birds can fly" are explicitly listed. How then do we as humans decide whether a particular bird can or cannot fly?

Ian Shi

Numerade Educator

Problem 51

Explain how the meaning of the sentence "I read the new tax law" depends on the context.

Samuel Goyette

Numerade Educator

Problem 52

Describe how the problem of traveling from one city to another could be framed as a production system. What are the states? What are the productions?

Srikar Katta

Numerade Educator

Problem 53

Suppose you must perform three tasks, $A, B$ and $C,$ that can be performed in any order (but not simultaneously). Describe how this problem can be framed as a production system and draw its state graph.

Christine Tabor

Christine Tabor

Numerade Educator

Problem 54

How does the state graph in the previous problem change if task C must be performed before task B?

Carlos Pinilla

Numerade Educator

Problem 55

a. If the notation $(i, j),$ where $i$ and $j$ are positive integers, is used to mean "if the entry in the $i$ th position in the list is greater than the entry in the $j$ th position, interchange the two entries," which of the following two sequences does a better job of sorting a list of length three? (1,3)(3,2)
(1,2)(2,3)(1,2)
b. Note that by representing sequences of interchanges in this manner, sequences can be broken into sub-sequences that can then be reconnected to form new sequences. Use this approach to describe a genetic algorithm for developing a program that sorts lists of length ten.

Clarissa Noh

Numerade Educator

Problem 56

Suppose each member in a group of robots is to be equipped with a pair of sensors. Each sensor can detect an object directly in front of it within a range of two meters. Each robot is shaped like a round trash can and can move in any direction. Design a sequence of experiments to determine where the sensors should be placed to produce a robot that successfully pushes a basketball in a straight line. How does your sequence of experiments compare to an evolutionary system?

Kendrick Buford

Kendrick Buford

Numerade Educator

Problem 57

Do you tend to make decisions in a reactive or plan-based mode? Does your answer depend on whether you are deciding on what to have for lunch or making a career decision?

Samuel Goyette

Numerade Educator