(复杂系统的性能评价与优化课件资料）General_search_strategies

1、( (复杂系统的性能复杂系统的性能评价与优化课件评价与优化课件资料）资料）General_search_General_search_strategiesstrategiesf1f2f3f4f5f6f7f8x100010111x200101011x301001101f1f2f3f4f5f6f7f8x100010111x200101011x301001101X2X12111Total computation effort consumed:2+2+2+1+2+1+1+1Number of successes : 6f1f2f3f4f5f6f7f8x100010111x200101011x3010

2、01101S0S1S2S3f1f2f3f4f5f6f7f8x100010111x200101011x301001101X XX X2 21 12 21 11 11 1X X2 2X X1 12 21 11 11 1S0S1S2S3NSRGnkSPk0;n is the number of solutions.Sk is the set of binary strings with exactly k 1s. is 1 if the problem instance f has outcome 1 for at least one solution in the randomly picked

3、P solutions x1,x2,xP.P;x1x2x|X|f1f2f|F|0010001101011111Parallel searchParallel search allow several search procedures work simultaneously.f1f2f3f4f5f6f7f8x100010111x200101011x301001101P1 is a search procedureP2 is another search procedureP12: the iterative search processFor each search step of both

4、procedures, results are reported to the controller.P1P2P1P2cf1f2f3f4f5f6f7f8x100010111XXX1X111x200101011x301001101X1XX11X1f1f2f3f4f5f6f7f8x100010111XXX1X111x200101011x301001101X1XX11X1X2X22222Total computation effort consumed:2+2+2+2+2+2+2+2Number of successes: 6P12P2P1n is the number of solution.Sk

5、 is the set of binary strings with exactly k 1s. is 1 if the problem instance f has outcome 1 for at least one design in P1 designs (decided by neighborhood search). is defined similarly.,max21;0;PnkSPk ,max21;0;PnkSPk nkSPPk0;21=1;P2;Px1x2x|X|f1f2f|F|0010001101011111HybridSimple search strategies c

6、an also be combined.n is the number of solutions.Sk is the set of binary strings with exactly k 1s. is 1 if the problem instance f has outcome 1 for at least one design in the randomly picked P1 designs. is defined similarly.,max21;0;PnkSPk ,max21;0;PnkSPk nkSPPk0;21=1;P2;PHill climbingThe purpose o

7、f hill climbing is to find the maximum outcome of the given instance by search in an increasing direction. If it find a maximum, we say it makes a hit.x1x2x|X|f1f2f|F|y1y1y1y1y1y2y|Y|y|Y|y|Y|y|Y-1|y|Y-1|y|Y-1|y|Y-1|y|Y-1|y|Y|fx10 x21x32x43x52x64xn0f1f2f3f4f5x101012x210120 x301201x412010 x520101321XX54321HCNSBack trackingThe purpose of back tracking is to return to a history point and picku