ARTIFICIAL INTELLIGENCE

Transcription

1 ARTIFICIAL INTELLIGENCE AN INTRODUCTION Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 1

2 Course Logistics Course Description This course will introduce the basics of Artificial Intelligence(AI), its scope and application domains and principles. Course Material Required: S. Russell and P. Norvig, Artificial Intelligence: A Modern Approach 2nd Edition Reference: George F Luger, Artificial Intelligence: Structures and Strategies for Complex Problem-solving 5th Edition Elaine Rich and Kevin Knight, Artificial Intelligence: 3rd Edition Prerequisite Data Structures Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 2

3 Course Logistics Instructor Zahid Iqbal Room # B211 (zahid.iqbal@uog.edu.pk) BS (CS) Punjab University (Gold Medalist) MS (CS) FAST University Islamabad Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 3

4 Course Logistics Grading Policy Sessional 25% Mid Term 25% Final 50% Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 4

5 Course Contents Outline Introduction to Artificial Intelligence Knowledge Representation Propositional Logic Predicate Calculus Search Methods Learning Languages for AI (Prolog, LISP) Natural Language Processing Automated Reasoning Knowledge Based Systems... Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 5

6 INTRODUCTION Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 6

7 Intelligence What is Intelligence? Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 7

8 Intelligence (Attempted Definitions) Intelligence is an umbrella term used to describe a property of the mind that encompasses many related abilities, such as the capacities to reason, to plan, to solve problems, to think abstractly, to comprehend ideas, to use language, and to learn. The ability to learn, reason, and problem solving. Debate revolves around the nature of intelligence as to whether it is an innate quality or something that is developed as a result of interacting with the environment. Many researchers believe that it is a combination of the two. Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 8

9 Intelligence (Attempted Definitions) Intelligence refers to the various verbal and nonverbal skills and aptitudes one uses to cope with, interact with, and manipulate the outside world. Intelligence is effectively perceiving, interpreting and responding to the environment. It is also taken to mean the ability of an organization to survive and meet desired goals and objectives. Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 9

10 Artificial Intelligence AI may be defined as the branch of computer science that is concerned with the automation of intelligent behavior. The major problem in defining the AI are : proper definition of intelligence itself. Is intelligence a single faculty, or is it a name for a collection of distinct and unrelated abilities? Exactly what happens when learning occurs? What is creativity? What is intuition? Can intelligence be inferred from observable behavior, or does it require evidence of a particular internal mechanism? Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 10

11 Artificial Intelligence Is it necessary to pattern an intelligent computer program after what is known about human intelligence, or is a strict engineering approach to the problem sufficient? Is it even possible to achieve intelligence on a computer, or does an intelligent entity require the richness of sensation that might be found only in a biological existence? These are all unanswered questions and all of them have helped to shape the problems and solution methodologies that constitute the core of modern AI. Artificial intelligence is still a young discipline, and its structure, concerns and methods are not clearly defined than those of a more mature science such as physics. Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 11

12 History of AI The field of AI research was founded at a conference on the campus of Dartmouth College in1956. The attendees became the leaders of AI research for many decades. They and their students wrote programs that were, to most people, simply astonishing: Computers were solving word problems in algebra, proving logical theorems and speaking English. By the middle of the 1960s, research in the U.S. was heavily funded by the Department of Defense and laboratories had been established around the world. AI's founders were profoundly optimistic about the future of the new field: Herbert Simon predicted that "machines will be capable, within twenty years, of doing any work a man can do. Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 12

13 History of AI They had failed to recognize the difficulty of some of the problems they faced. In 1974, in response to the criticism of Sir James and ongoing pressure from the US Congress to fund more productive projects, both the U.S. and British governments cut off all undirected exploratory research in AI. The next few years, when funding for projects was hard to find, would later be called the "AI winter". In the early 1980s, AI research was revived by the commercial success of expert systems, a form of AI program that simulated the knowledge and analytical skills of one or more human experts. By 1985 the market for AI had reached over a billion dollars. At the same time, Japan's fifth generation computer project inspired the U.S and British governments to restore funding for academic research in the field. However, beginning with the collapse of the Lisp Machine market in 1987, AI once again fell into disrepute, and a second, longer lasting AI winter began. Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 13

14 History of AI In the 1990s and early 21st century, AI achieved its greatest successes. Artificial intelligence is used for logistics, data mining, medical diagnosis and many other areas throughout the technology industry. The success was due to several factors: the increasing computational power of computers, a greater emphasis on solving specific sub problems, the creation of new ties between AI and other fields working on similar problems Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 14

15 Strong AI and Weak AI Strong AI means that machines act intelligently and they have real conscious minds. Weak AI says that machines can be made to act as if they are intelligent. Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 15

16 Success Stories Deep Blue defeated the reigning world chess champion Garry Kasparov in 1997 During the 1991 Gulf War, US forces deployed an AI logistics planning and scheduling program that involved up to 50,000 vehicles, cargo, and people NASA's on-board autonomous planning program controlled the scheduling of operations for a spacecraft Proverb solves crossword puzzles better than most humans Robot driving: DARPA grand challenge : face recognition software available in consumer cameras Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 16

17 Example: DARPA CHALLENGE Grand Challenge Cash prizes ($1 to $2 million) offered to first robots to complete a long course completely unassisted Stimulates research in vision, robotics, planning, machine learning, reasoning, etc Grand Challenge: 150 mile route in Nevada desert Furthest any robot went was about 7 miles but hardest terrain was at the beginning of the course 2005 Grand Challenge: 132 mile race Narrow tunnels, winding mountain passes, etc Stanford 1 st, CMU 2 nd, both finished in about 6 hours 2007 Urban Grand Challenge In Victorville, California Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 17

18 Stanley Robot Stanford Racing Team

19 2004: Barstow, CA, to Primm, NV 150 mile off-road robot race across the Mojave desert Natural and manmade hazards No driver, no remote control Fastest vehicle wins the race (and 2 million dollar prize)

20 HAL: from the movie 2001 HAL part of the story centers around an intelligent computer called HAL HAL is the brains of an intelligent spaceship in the movie, HAL can speak easily with the crew see and understand the emotions of the crew navigate the ship automatically diagnose on-board problems make life-and-death decisions display emotions In 1969 this was science fiction: is it still science fiction? Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 20

21 Can we build hardware as complex as the brain? Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 21

22 Can we build hardware as complex as the brain? How complicated is our brain? a neuron, or nerve cell, is the basic information processing unit estimated to be on the order of neurons in a human brain many more synapses (10 14 ) connecting these neurons cycle time: 10-3 seconds (1 millisecond) How complex can we make computers? 10 8 or more transistors per CPU supercomputer: hundreds of CPUs, bits of RAM cycle times: order of 10-9 seconds Conclusion YES: in the near future we can have computers with as many basic processing elements as our brain, but with far fewer interconnections (wires or synapses) than the brain much faster updates than the brain but building hardware is very different from making a computer behave like a brain! Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 22

23 Points Ratings Can Computers beat Humans at Chess? Chess Playing is a classic AI problem well-defined problem very complex: difficult for humans to play well 3000 Deep Blue 2800 Human World Champion Deep Thought Ratings Conclusion: YES: today s computers can beat even the best human Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 23

24 Can Computers Talk? This is known as speech synthesis translate text to phonetic form e.g., fictitious -> fik-tish-es use pronunciation rules to map phonemes to actual sound e.g., tish -> sequence of basic audio sounds Difficulties sounds made by this lookup approach sound unnatural sounds are not independent e.g., act and action modern systems (e.g., at AT&T) can handle this pretty well a harder problem is emphasis, emotion, etc. humans understand what they are saying machines don t: so they sound unnatural Conclusion: NO, for complete sentences YES, for individual words Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 24

25 Can Computers see? Recognition v. Understanding (like Speech) Recognition and Understanding of Objects in a scene look around this room you can effortlessly recognize objects human brain can map 2d visual image to 3d map Why is visual recognition a hard problem? Conclusion: mostly NO: computers can only see certain types of objects under limited circumstances YES for certain constrained problems (e.g., face recognition) Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 25

26 Intelligent Systems in Everyday Life Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 26

27 Intelligent Systems in Everyday Life Customer Service automatic voice recognition The Web Identifying your age, gender, location, from your Web surfing Automated fraud detection Digital Cameras Automated face detection and focusing Computer Games Intelligent characters/agents Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 27

28 Different Types of Artificial Intelligence 1.Modeling exactly how humans actually think 2.Modeling exactly how humans actually act 3.Modeling how ideal agents should think 4.Modeling how ideal agents should act Modern AI focuses on the last definition we will also focus on this engineering approach success is judged by how well the agent performs Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 28

29 Thinking humanly Cognitive Science approach Try to get inside our minds E.g., conduct experiments with people to try to reverse-engineer how we reason, learning, remember, predict Problems Humans don t behave rationally The reverse engineering is very hard to do The brain s hardware is very different to a computer program Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 29

30 Acting humanly: Turing test Turing (1950) "Computing machinery and intelligence "Can machines think?" "Can machines behave intelligently? Operational test for intelligent behavior: the Imitation Game Suggests major components required for AI: - knowledge representation - reasoning, - language/image understanding, - learning Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 30

31 Summary of Today s Lecture Artificial Intelligence involves the study of: automated recognition and understanding of signals reasoning, planning, and decision-making learning and adaptation AI has made substantial progress in recognition and learning some planning and reasoning problems but many open research problems AI Applications improvements in hardware and algorithms => AI applications in industry, finance, medicine, and science. Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 31

32 References Artificial Intelligence: Structures and Strategies for Complex Problem Solving Chapter 1 Artificial Intelligence 2012 Lecture 01 Delivered By Zahid Iqbal 32