SLIDE 1 50 50th
th AIAA Conference, Palm Springs, CA, May
AIAA Conference, Palm Springs, CA, May 2009 2009
Stochastic Computing by Stochastic Computing by a New Polynomial a New Polynomial Dimensional Decom Dimensional Decomposition Method
Sharif Rahman Sharif Rahman The The University University of
Iowa
p
The The University University of
Iowa Iowa City, IA 52245 Iowa City, IA 52245
Work supported by Work supported by NSF (DMI-0355487 and CMMI-0653279) NSF (DMI-0355487 and CMMI-0653279)
SLIDE 2
OUTLINE OUTLINE
Introduction Introduction Polynomial Dimensional Polynomial Dimensional Decomposition (PDD) Method Decomposition (PDD) Method Examples Examples Conclusions & Conclusions & Future Work Future Work
SLIDE 3
INTRODUCTION INTRODUCTION
Dimensional Decomposition (Hoeffding, 1948) Dimensional Decomposition (Hoeffding, 1948)
NONLINEAR NONLINEAR SYSTEM
SLIDE 4
INTRODUCTION INTRODUCTION
Existing Component Functions (Xu/Rahman) Existing Component Functions (Xu/Rahman)
SLIDE 5
PDD METHOD PDD METHOD
Orthonormal (ON) Polynomial Basis Orthonormal (ON) Polynomial Basis
SLIDE 6 PROPOSED METHOD PROPOSED METHOD
Cl Cl i l O h l P l i l Cl Class assica cal Ort rthogona
ynomials
SLIDE 7
PROPOSED METHOD
Fourier-Polynomial Expansions Fourier-Polynomial Expansions
SLIDE 8
PROPOSED METHOD PROPOSED METHOD
Polynomial Dimensional Decomposition Polynomial Dimensional Decomposition
SLIDE 9
PROPOSED METHOD
Formulation of Coefficients Formulation of Coefficients
SLIDE 10
PROPOSED METHOD PROPOSED METHOD
Dimension-Reduction Integration Dimension-Reduction Integration
SLIDE 11
PROPOSED METHOD PROPOSED METHOD
Dimension-Reduction Integration Dimension-Reduction Integration
SLIDE 12 PROPOSED METHOD C i C i l Eff Computat
Effort
Approx Approximat ation No.
- . of Funct
- f Function Evaluat
- n Evaluations
- ns
Cost Scali
Univariate Bivariate
… … …
S-variate
SLIDE 13 EXAMPLES EXAMPLES
A C A C bi P l i l A Cubi bic c Polynom ynomial
0.5 0 3 0.4 0.5
N(0,1) U(- B(-3,+3,3,3) B(-5,+5,1,1)
0.2 0.3
fi(xi)
1 2 3 4
x
0.0 0.1 i = 0, i = 1
xi
SLIDE 14 EXAMPLES EXAMPLES
T il P b bili bili i Tail il Pro robabili bilities es
10 0 10 0 10 -1 10 0
Gaussian-Hermite m = 3, n = 4 Monte Carlo
10 -1 10 0
Uniform-Legendre m = 3, n = 4
10 -3 10 -2
FY(y) Univariate Bivariate Trivariate
10 -3 10 -2
FY(y) Monte Carlo
10 -5 10 -4 10 -5 10 -4
Univariate Bivariate Trivariate
50 100
y
10 20 30 40 50 60 70 80
y
SLIDE 15 EXAMPLES EXAMPLES
T il P b bili bili i Tail il Pro robabili bilities es
10 0 10 0 10 -1 10 0
Beta-Jacobi (-3 xi 3;
= = 3)
m = 3, n = 4
10 -1 10 0
Beta-Jacobi (-5 xi 5; = = 1) m = 3, n = 4
10 -3 10 -2
FY(y) Monte Carlo
10 -3 10 -2
FY(y) Monte Carlo U i i
10 -5 10 -4
Univariate Bivariate Trivariate
2 2 100 10 -5 10 -4
Univariate Bivariate Trivariate
40 80 120
y
25 50 75 100
y
SLIDE 16 EXAMPLES EXAMPLES
Piezoelectric Piezoelectric Transducer Transducer Piezoelectric Piezoelectric Transducer Transducer
Brass cap 3 mm 12.5 mm Electroded Ceramic Brass cap 12.5 mm 3 mm Electroded surfaces 11 mm 11 mm 1.5 mm 1.5 mm Brass cap Ceramic
SLIDE 17
EXAMPLES EXAMPLES
A F A F M d Sh (M I ) A Few ew Mode e Sh Shapes apes (M (Mean ean Input nput)
SLIDE 18 EXAMPLES EXAMPLES
M i M i l Di ib i f F i Marg argina nal Di Distr strib ibut utions o
requencies es
0 18 10 0 0 12 0.18 f1 Monte Carlo (5000) Univariate (m=3) Bivariate (m=3) 10 -1 10 F1 F2 F3 F4 0.06 0.12
fi(i)
f2 f3 f4 f5 f 10 -3 10 -2
Fi(i)
4
Monte Carlo (5000) F5 F6 20 40 60 80 100 120 140 0.00 f6 10 -5 10 -4 ( ) Univariate (m=3) Bivariate (m=3) 20 40 60 80 100 120 140
i, kHz 20 40 60 80 100 120 140 i, kHz
SLIDE 19 EXAMPLES EXAMPLES
J i J i Di ib i f F i Joint nt Di Distr strib ibut utions o
requencies es
SLIDE 20 CONCLUSIONS/FUTURE WORK CONCLUSIONS/FUTURE WORK
A new polynomial dimensional decomposition A new polynomial dimensional decomposition method was developed method was developed
- Decomposition with increasing dimensions
- Fourier-polynomial expansions
- Innovative dimension-reduction integration
No sample points required; yet, generates No sample points required; yet, generates convergent approximations convergent approximations Accurate with modest com Accurate with modest computational effort utational effort p Future work: Future work: Time-variant problems, arbitrary Time-variant problems, arbitrary b bilit ilit di ti & pro probabilit bility measures, y measures, di discon sconti tinuous nuous & non- non- smooth responses, smooth responses, etc etc.