A I (Artificial Intelligence) Professor I. J. Chung 2018-07-02

AI (Artificial Intelligence) Study of mental thinking & facilities with appropriate computational models Solve the real world problems (see below). Fundamental assumption of AI : What the brain of human beings may be thought of at some level as a kind of computations. Another definition of AI One of major fields of computer science that makes it possible to perceive, think, reason and act. (cognitive science, psychology) 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) Emphasis an computation, reasoning, action, etc. Task domain of AI – mundane tasks Perception : vision, speech Natural language processing : understanding, generation, translations, semantic modeling Common sense reasoning Robot control 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) Formal tasks Automated reasoning with formal logic Game : chess, go, tic-tac-toe, etc. Mathematics geometry, logic, calculus, proving properties of programs 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) Expert tasks Engineering : design, fault findings, manufacturing, planning Scientific analysis : Medical diagnosis & analysis Financial analysis & planning 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) Machine learning symbol-based : ID3 (decision tree), inductive bias, COBWEB, explanation-based learning Connectionist : artificial neural networks Social based : genetic algorithm (Darwinism with competition) Emergent : agent 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) Eg. Analogy problems A B C 1 2 3 4 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) AI language LISP ( functional declarative language ) Prolog ( logic declarative language ) LISP Flexible language for symbolic manipulation rather than numeric computations Functional programming language based on λ - expression (McCarthy, of MIT 1965) Interpreted language as opposed to compiled language Widely used in ES/KBS, reasoning & learning, NLP, etc. cf: Prolog (logic programming lang.) 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) Basic Lisp Primitives Atom : fundamental objects in LISP without parenthesis E.g. OK 3 1.6 I List : collection of atom enclosed by parenthesis (nesting is allowed) (I AM A BOY) (I (LOVE) YOU) (1.5) Operator : arguments with lists (prefix notation) (+ 4 2) (* 6 3) (/ (+ 4 2) (* 6 3)) 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) Basic Lisp Primitives (cont.) Procedure : basic program unit in LISP Primitive : procedure supplied by LISP itself Program : collection of procedures to solve a particular job expression integer symbol number list atom real 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) CAR & CDR (CAR ’(I AM A BOY)) I (CAR ’((I) AM A BOY)) (I) (CAR ’((A B) C)) (A B) (CDR ’(I AM A BOY)) (AM A BOY) (CDR ’((I) AM A BOY)) 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) CAR & CDR (cont.) (CDR ’((A B) C)) (C) (CDR ’(I)) ( ) (CADR ’(A B C)) ≡ (CAR (CDR ‘(A B C))) (SETQ L ’(A B)) ; assignment statement in LISP with L side- effects (A B) 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) APPEND : strings together the elements of all lists supplied as arguments (SETQ L ’(A B)) (A B) (APPEND L L) (A B A B) (APPEND L L L) (A B A B A B) (APPEND ’(A) ’( ) ’(B) ’( )) (APPEND ’((A) (B)) ’((C) (D))) ((A) (B) (C) (D)) 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) LIST : makes a list out of a its arguments. Each argument becomes an elements of the new list (SETQ L ’(A B)) (LIST L L) ((A B) (A B)) (LIST L L L) ((A B) (A B) (A B)) (LIST ’L L) (L (A B)) (LIST ’((A) (B)) ’((C) (D))) (((A) (B)) ((C) (D))) 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) CONS : takes a list and insert a new first element. CONS is a mnemonic for list constructor. (CONS <new first element> <some list>) (CONS ’A ’(B C)) (A B C) (CAR (CONS ’A ’(B C))) A (CDR (CONS ’A ’(B C))) (B C) Note : assume that L is a list. Then, (CONS (CAR L) (CDR L)) ≡ L 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) (APPEND ’(A B) ’(C D)) (A B C D) (LIST ’(A B) ’(C D)) ((A B) (C D)) (CONS ’(A B) ’(C D)) ((A B) C D) (SETQ L ’(A B)) (LIST L L) ((A B) (A B)) (CONS L L) ((A B) A B) 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) (APPEND L L) (A B A B) (LIST ’L L) (L (A B)) (APPEND ’L L) ERROR (CONS ’L L) (L A B) 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) LENGTH, REVERSE, SUBST, LAST LENGTH : number of top-level elements in a list e.g (LENGTH ’(A B)) 2 (LENGTH ’((A B) (C D))) (SETQ L ’(A B)) (LENGTH L) (LENGTH (APPEND L L)) 4 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) LENGTH, REVERSE, SUBST, LAST REVERSE : turns the top level of a list around e.g (REVERSE ’(A B)) (B A) (REVERSE ’((A B) (C D))) ((C D) (A B)) (REVERSE L) (REVERSE (APPEND L L)) (B A B A) 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) LENGTH, REVERSE, SUBST, LAST SUBST : takes 3 arguments, the last of which is an expression in which occurrences of a specified atom are to be replaced. The first argument is the new expression to be plugged-in; the second argument is the atom to be replaced. (SUBST <new exp> <old atom> <exp to substitute in>) 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) e.g (SUBST ’A ’B ’(A B C)) (A A C) (SUBST ’B ’A ’(A B C)) (B B C) (SUBST ’A ’X (SUBST ’B ’Y ’(SQRT (+ (* X X) (* Y Y))))) (SQRT (+ (* A A) (* B B))) 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) LENGTH, REVERSE, SUBST, LAST LAST : returns a list that contains only the last element of the list as the argument. e.g (LAST ’ (A B C)) (C) (LAST ’((A B) (C D))) ((C D)) (LAST ’A) Error 2018-07-02 Artificial Intelligence

AI (Artificial Intelligence) Procedure abstraction is done by using DEFUN to combine ingredients. (DEFUN <procedure - name> (<para-1> <para-2> … <para-n>) <procedure-body>) e.g (DEFUN F_TO_C (TEMP) (/ (- TEMP 32) 1.8)) (F-TO-C 32) (DEFUN EXCHANGE (PAIR) (LIST (CADR PAIR) (CAR PAIR)))) (EXCHANGE ’(ADAM EVE)) (EVE ADAM) 2018-07-02 Artificial Intelligence