Artificial intelligence
- 1. UNIT-1ST INTRODUCTION AND SOLVING PROBLEMS What is Artificial Intelligence? The study of computer systems that attempts to model and apply the intelligence of the human mind. A branch of computer science dealing with the simulation of intelligent behavior in computers. OR Artificial Intelligence is the intelligence of machines and branch of computers science that aims to create it. Applications of Artificial Intelligent Robotics Robots are able to perform the tasks given by a human. They have sensors to detect physical data from the real world such as light, heat, temperature, movement, sound, bump, and pressure. Expert System There are some applications which integrate machine, software, and special information to impart reasoning and advising. They provide explanation and advice to the users.
- 2. Characteristics of Expert Systems • High performance • Understandable • Reliable • Highly responsive Speech Recognition Some intelligent systems are capable of hearing and comprehending the language in terms of sentences and their meanings while a human talk to it. Games AI plays crucial role in strategic games such as chess, poker, tic-tac-toe, etc., where machine can think of large number of possible positions based on heuristic knowledge. Handwriting Recognition The handwriting recognition software reads the text written on paper by a pen or on screen by a stylus. It can recognize the shapes of the letters and convert it into editable text. Goals of AI • To Create Expert Systems − The systems which exhibit intelligent behavior, learn, demonstrate, explain, and advice its users. • To Implement Human Intelligence in Machines − Creating systems that understand, think, learn, and behave like humans.
- 4. Advantages of Artificial Intelligence Disadvantages of Artificial Intelligence
- 5. Types of Artificial Intelligence 1. Weak AI or Narrow AI: It is focused on one narrow task, the phenomenon that machines which are not too intelligent to do their own work can be built in such a way that they seem smart. An example would be a poker game where a machine beats human where in which all rules and moves are fed into the machine. Here each and every possible scenario need to be entered beforehand manually. Each and every weak AI will contribute to the building of strong AI.
- 6. 2. Strong AI: The machines that can actually think and perform tasks on its own just like a human being. There are no proper existing examples for this but some industry leaders are very keen on getting close to build a strong AI which has resulted in rapid progress.
- 7. Difference Between the Human and Machine Intelligence 1. Machines do not have life, as they are mechanical. On the other hand, humans are made of flesh and blood; life is not mechanical for humans. 2. Humans have feelings and emotions, and they can express these emotions. Machines have no feelings and emotions. They just work as per the details fed into their mechanical brain. 3. Humans can do anything original, and machines cannot. 4. Humans have the capability to understand situations, and behave accordingly. On the contrary, machines do not have this capability. 5. While humans behave as per their consciousness, machines just perform as they are taught. 6. Humans perform activities as per their own intelligence. On the contrary, machines only have an artificial intelligence Intelligent Agent An agent is anything that can perceive its environment through sensors and acts upon that environment through effectors.
- 8. The Structure of Intelligent Agents Agent’s structure can be viewed as − • Agent = Architecture + Agent Program • Architecture = the machinery that an agent executes on. • Agent Program = an implementation of an agent function. Approaches of Artificial Intelligence • System that think like Human/Thinking Humanly/Cognitive Modeling Approach • System that act like Human/Acting Humanly/Turing Test Approach • System that think Rationally/Thinking Rationally/Laws of Thought Approach • System that act Rationally/Acting Rationally/The Rational Agent Approach
- 9. #Cognitive Approach • We must have some ways that how humans think. • There are two ways to do this: 1) Through Introspection(try to catch our own thoughts). 2) Through Psychological experiments.
- 10. # Turing Test Machine • Proposed by Alan Turing in 1950. • To check whether the computer is really intelligent or not. • A computer passes the test if a human interrogator, after posing some written questions, cannot tell whether the written responses come from a person or not. • He proposed that “Turing test is used to determine whether or not computer(machine) can think intelligently like human”?
- 11. Imagine a game of three players having two humans and one computer, an interrogator (as human) is isolated from other two players. The interrogator job is to try and figure out which one is human and which one is computer by asking questions from both of them. To make the things harder computer is trying to make the interrogator guess wrongly. In other words, computer would try to indistinguishable from human as much as possible. If interrogator wouldn’t be able to distinguish the answers provided by both human and computer then the computer passes the test and machine(computer) is considered as intelligent as human. # Laws of Thought Approach • The Greek Philosopher Aristotle first attempted to codify right thinking. • Example: • Socrates is a man; all men are mortal; therefore, Socrates is mortal. • These laws of thought were supposed to govern the operation of the mind; their study initiated the field called logic. # The Rational Agent Approach • A rational agent is one that acts so as to achieve the best outcome or when there is uncertainty, the best expected outcome. • All the skills needed for the Turing Test also allow an agent to act rationally. • Knowledge representation and reasoning enable agents to reach good decisions. The rational-agent approach has two advantages over the other approaches. First, it is more general than the “laws of thought” approach because correct inference is just one of several possible mechanisms for achieving rationality. Second, it is more amenable to scientific development than are approaches based on human behavior or human thought. Problem Solving/Formulating Problems
- 12. According to psychology, “a problem-solving refers to a state where we wish to reach to a definite goal from a present state or condition.” Or According to computer science, a problem-solving is a part of artificial intelligence which encompasses a number of techniques such as algorithms, heuristics to solve a problem. Steps performed by Problem-solving agent Goal Formulation: It is the first and simplest step in problem-solving. It organizes the steps/sequence required to formulate one goal out of multiple goals as well as actions to achieve that goal. Problem Formulation/Set of Operations/Set of Actions/Intermediate State: It is the most important step of problem-solving which decides what actions should be taken to achieve the formulated goal. Initial State: It is the starting state or initial step of the agent towards its goal. Path cost: It assigns a numeric cost to each path that follows the goal.(one per move/one per action). # 8 puzzle problem 8 Puzzle Problem: Here, we have a 3×3 matrix with movable tiles numbered from 1 to 8 with a blank space. The tile adjacent to the blank space can slide into that space. The objective is to reach a specified goal state similar to the goal state, as shown in the below figure. Initial State: We can start from any state as the initial state. • Goal test: It identifies whether we have reached the correct goal-state. • Path cost: The path cost is one per move. • Problem Formulation/Set of Operations/Set of Actions/Intermediate State:
- 13. # water jug problem A Water Jug Problem: You are given two jugs, a 4-gallon one and a 3-gallon one, a pump which has unlimited water which you can use to _ll the jug, and the ground on which water may be poured. Neither jug has any measuring markings on it. How can you get exactly 2 gallons of water in the 4-gallon jug? Initial State: We have 4-gallon one and 3-gallon one and a pump which has unlimited water. • Goal test: exactly 2 gallons of water in the 4-gallon jug • Path cost: The path cost is one per action. • Problem Formulation/Set of Operations/Set of Actions/Intermediate State:
- 14. # missionaries and cannibals’ problem On one bank of a river are three missionaries and three cannibals. There is one boat available that can hold up to two people and that they would like to use to cross the river. If the cannibals ever outnumber the missionaries on either of the river’s banks, the missionaries will get eaten. How can the boat be used to safely carry all the missionaries and cannibals across the river? Initial State: On one bank of a river are three missionaries and three cannibals. There is one boat available. Goal test: we have to go another place. • Path cost: The path cost is one per action or one per move. • Problem Formulation/Set of Operations/Set of Actions/Intermediate State: