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ComputerAided_Design_Engineering_amp_Manufactur.pdf

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Note that control transitions are output transitions of the prime start place, denoted , of and ,<br />

and tj must be a control transition. Let CT be the set of control transitions. Procedure “find_prime_start<br />

gj<br />

( tg, tj) ” is to find pps .<br />

gj<br />

1. pps � find_prime_start ( tg, tj ){<br />

Select one input place pin of tj such that<br />

( pin → tg) ,<br />

gj<br />

then pin is the pps ;<br />

}<br />

2. find_CT(){ gj<br />

CT � { t | t � ( pps) •}.<br />

}<br />

The time complexities for “find_prime_start ( tg, tj) ” and “find_CT()” are both O(n).<br />

During the process of constructing the cycle, each new TT-path must have its tj , a control transition<br />

( i.e., tj � CT) . It is desired that we generate these new TT-paths in a continuous fashion; i.e., it is better<br />

not to construct the cycle in a piecewise fashion. Let � be the PSP that has just been generated with<br />

and . The and for the next new PSP must satisfy the following conditions:<br />

w�<br />

t�g t� j tg tj 1. t� j → tg .<br />

2. tj must be a control transition<br />

3. tj � tc, tc�C T and tc � tj All such are colored “brown” for the designer to pick. Afterwards, all such brown transitions will<br />

be colored “black.” Procedure “color_generation_transitions()” extracted from our source code is to color<br />

all above .<br />

t g<br />

t g<br />

void color_generation_transitions (num,num1)<br />

int num,num1;<br />

{ int i,j,k;<br />

for(i�1;i��;i��)<br />

{<br />

/ �find PSP that are sequential later than PSP num1 and<br />

concurrent to PSP num� /<br />

if(T_Matrix[i][num1]��1 � T_Matrix[i][num1]��’N’�<br />

T_Matrix[i][num1]��’L’) {<br />

for(each �k�CT){ if(T_Matrix [i][k]!�’X’)<br />

continue;/ �failed try a new i� /<br />

}<br />

/ �so far, �i � all PSP in C �<br />

T /<br />

for(each transition tj in PSP i)<br />

}<br />

} }<br />

strcpy(color[j],“brown”);/ �color brown� ti /<br />

t� j<br />

where num1 are the PSP containing , �i the total number PSPs, and T_Matrix[a][b] the temporal<br />

relationship between �a and �b. The total time complexity of the above procedure is O � .<br />

2<br />

( )<br />

(D.2) GPN<br />

We now consider how to implement the arc-ratio rule. Upon the generation of an NP, its least ratio in<br />

the NP must be literally smaller than that in N1 . This causes extra computation of the least ratio in N1 .<br />

To do so, we have to search all paths between ng and nj , which is quite time consuming (called the<br />

canonical method for later reference). To avoid this, we select a reference node and choose it to be the<br />

gj<br />

pps t g<br />

t j

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