lee

chef                blacknoodle(yes)

    짬뽕(no)

we

lee

chef2:            짜(yes)

  짬(yes)

짜  cand 짬        짬(yes)

---------------------------

problem:

java application

자바경우 cand(초이스 앤드)경우 어떤게 이득?

Web page:

동아대는 학생수가...웹페이지에 초이스앤드 경우 이점?

add(x,y): int cand

and(x,y): float

---------------------------------------------------

Web page:  같은 뜻 단어 둘 중 하나 골라도 된다. ex)영어,한글

ex1) night cand nite

ex2) donga web page->engliweb cand koreanwob

recursion vs nonrecursion

recursion

rule1: fib(1)=0

rule2: fib(2)=1

rule3: fib(n)=fib(n-1)+fib(n-2)

main(){

fib(50);

}

prob: redundancy  ,  n-1과 n-2 양쪽에서 중복된 계산 발생

 norecursion:

fib(n)=tmp1=0

temp2=1;

for i=3 to n

tmp = tmp1+tmp2

tmp1=tmp2;

tmp2=tmp

prob1: lengthy code , 피보나치 규칙이 명확히 안보인다.

최종판

rule1: fib[1]=0

rule2: fib[2]=1

rule3: fib[n]=fib[n-1]+fib[n-2]

rule4: fib[3]=2

main()

{

for i=3 to n

fib[n]=fib[i-1]+fib[n-2]

}

choice or,and sequential or,and

A->(imply) B

ex) lee: ham                lee는 햄버거 만들 수 잇다

lee: 3000->ham       lee는 3000원이 있으면 햄버거 만들 수 있다

ex)chinese restaurant:

5000->(짜장 xor 짬뽕)

chinese restaurant        짜(x)

짬(x)

5000->짜(yes)

specification continued:

--------------------------------------------------

sw engineer            customer:

dynamic knowledgebase:

knowledge base changes constantly

app:<---- yahoo

<---clear or cloudy

specification output:

 objects : yahoo: clear seq-or cloudy

 main: clear seq-or cloudy

app: yahoo에서 실시간으로 날씨 정보를 받아 그대로 display하라

Q: Java: leader:

A Seq-or B : it claims A is true. But at some later point, it can change its mind so that it claims B is ture

examples : A seq-or B

가로등: on seq-or off

door : open seq-or off

----------------------------

A seq-and B: it claims A is true but at some later point, the uwer changes its mind and make the machine claim B.

examples:

switch: on seq-and off.

tom 객체

tom : (alive seq-or dead)  죽는거 tom결정

(alive seq-and dead) 죽는거 다른사람 결정

(alive seq-or dead) seqand (alive seq-and dead)    앞에서 죽을경우 살수 없기 때문에  이 경우는 잘못됨

(divorced seq-or married) seqor (divorced

Q: What is the most important topic/ concept in IT?

=>

semantic web

=====================================

ex) SW developer coustomer:

Given a set of integers S and a number K,

sumofsubset(S,K) is true if there is a subset {k1,..,kn} of  S such that k1+k2+..+kn=k.

ex) ss({3,5,6},8) = true  why? 3+5=8

     ss({3,4},10) = false   why? 3+4=7

-----------------------

constructive definition.

:원소

:: 집합 추가

rule 1. if for all k , ss({K},K) is true.

rule 2. if for all S:set, K:int,A:int, if ss(S,K), then ss(A::S, A)  

s에 a라는 원소 추가하고 k자리에 a적는다.

===================================================

내 생각추가{

rule 3. if ss({S},k) , then ss((s1-k)::S,k)

s가 1개면 s-k의 값을 s집합에 넣는다.

rule 4. if ss({S},k) , then ss({s},s1+s2)

S가 2개 이상이면 원소합을 K에 넣는다.  룰 1이랑 완전 비슷

}

===============================================

real tasks:

task1 decide whether

ss({2,4,7},9).

Prog -> ss({2,4,7},9)

task2 decide whether ss({2,4},10)

and ss({2,4},1) in parallel.

exec(prog->ss({2,4},10);

ss({2,4},1) par-and

ss(2,4},1)

reference : "In the beginning was game semantics" by Giorg Japaridze.

퀴즈

Q1 : people say C is based on function Java is based on _____

game

Q2: the difference between C and Java

suppose your C code has

10,000 function definitions.

f1=f2()

f2=f3()

f10000 = f9999()

=> program this in Java

Q3: the biggest problem in SW

app1 in Java

app2 in Android