CoNBONet: Conformalized Neuroscience-inspired Bayesian Operator Network for Reliability Analysis
Authors: Shailesh Garg, Souvik Chakraborty
Organizations: Department of Applied Mechanics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India. · Department of Applied Mechanics, Yardi School of Artificial Intelligence (YScAI), Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
Time-dependent reliability analysis of nonlinear dynamical systems under stochastic excitations is a critical yet computationally demanding task. Conventional approaches, such as Monte Carlo simulation, necessitate repeated evaluations of computationally expensive numerical solvers, leading to significant computational bottlenecks. To address this challenge, we propose CoNBONet, a neuroscience-inspired surrogate model that enables fast, energy-efficient, and uncertainty-aware reliability analysis, providing a scalable alternative to techniques such as Monte Carlo simulations. CoNBONet, short for Conformalized Neuroscience-inspired Bayesian Operator Network, leverages the expressive power of deep operator networks while integrating neuroscience-inspired neuron models to achieve fast, low-power inference. Unlike traditional surrogates such as Gaussian processes, polynomial chaos expansions, or support vector regression, that may face scalability challenges for high-dimensional, time-dependent reliability problems, CoNBONet offers fast and energy-efficient inference enabled by a neuroscience-inspired network architecture, calibrated uncertainty quantification with theoretical guarantees via split conformal prediction, and strong generalization capability through an operator-learning paradigm that maps input functions to system response trajectories. Validation of the proposed CoNBONet for various nonlinear dynamical systems demonstrates that CoNBONet preserves predictive fidelity, and achieves reliable coverage of failure probabilities, making it a powerful tool for robust and scalable reliability analysis in engineering design.
Figures & tables
Figure 1: Schematic for information flow in CoNBONet.
Figure 2: Ratio of energy consumed by densely connected ANN layer vs densely connected VSN layer, when run for a single Spike Time Step (STS). It is assumed that all output nodes will produce spikes.
Figure 3: Ratio of energy consumed by densely connected ANN layer vs densely connected VSN layer, when run for two STSs.
Figure 4: Mean prediction from the CoNBONet compared against the ground truth with calibrated confidence intervals shown as the blue patch, for example E-I.
Layer
A1
A2
1 st DOF
14.70
18.20
Table 1: Spiking activity (%) for the two layers (A1 and A2) of branch network when using CoNBONet for example E-I.
Model
Coverage (%)
Number of time steps with coverage
Avg.
Min.
Max.
<95%
≥95%
BONet
93.98
81.46
100.00
53
47
CoBONet
99.73
98.68
100.00
0
100
NBONet
97.56
89.00
99.98
2
98
CoNBONet
97.76
96.92
99.86
0
100
Table 2: Coverage provided by the confidence intervals generated using various network in example E-I.
Figure 5: Probability of failure at different time steps in example E-I.
Mass (kg)
Stiffness (N/m)
Damping (Ns/m)
m1=10
k1=10000
c1=100
m2=10
k2=10000
c2=100
m3=9
k3=9000
c3=90
m4=9
k4=9000
c4=90
m5=7.5
k5=7500
c5=75
Table 3: System parameters for Case-II: five-DOF (5-DOF) Duffing oscillator.
Figure 6: Mean prediction from the CoNBONet compared against the ground truth with calibrated confidence intervals shown as the blue patch, for example E-II.
Network
1 st DOF
2 nd DOF
3 rd DOF
4 th DOF
5 th DOF
BONet
0.0018
0.0019
0.0027
0.0009
0.0018
CoNBONet
0.0048
0.0060
0.0022
0.0044
0.0051
Table 4: NMSE for each degree of freedom obtained when comparing network predictions against the ground truth in E-II.
Layer
1 st DOF
2 nd DOF
3 rd DOF
4 th DOF
5 th DOF
A1
11.5
12.5
14.0
15.0
16.1
A2
17.5
14.0
16.2
22.5
16.4
Table 5: Spiking activity (%) for the two layers (A1 and A2) of the branch network in CoNBONet (Example E-II).
Coverage (%)
Number of time steps with coverage
DOF
Model
AvgCov
MinCov
MaxCov
<95% / ≥95 (%)
1 st
BONet
95.30
83.72
99.94
29 / 71
CoBONet
99.23
98.18
99.96
0 / 100
NBONet
98.37
97.54
100.00
0 / 100
CoNBONet
98.52
97.24
99.98
0 / 100
2 nd
BONet
92.97
75.78
100.00
59 / 41
Table 6: Coverage provided by the confidence intervals generated using various network in example E-II.
Figure 7: PoF obtained using FTTF analysis at various DOFs in E-II. The PoF is computed corresponding to different threshold vales at each DOF.
DOF 0
DOF 1
DOF 2
DOF 3
DOF 4
Threshold
0.25
0.48
0.67
0.82
0.91
True PoF
0.633
0.617
0.607
0.599
0.596
BoundsMean PoF
[0.584,0.736]0.628
[0.581,0.694]0.614
[0.569,0.685]0.603
[0.563,0.718]0.596
[0.557,0.694]0.593
Table 7: PoF obtained using FTTF analysis at various DOFs in E-II. The PoF is computed at each DOF, correspondin to a single set of threshold values.
Figure 8: Mean prediction from the CoNBONet compared against the ground truth with calibrated confidence intervals shown as the blue patch, for example E-III.
Network
5 th DOF
15 th DOF
35 th DOF
65 th DOF
75 th DOF
BONet
0.0083
0.0027
0.0021
0.0011
0.0004
CoNBONet
0.0088
0.0072
0.0125
0.1101
0.0132
Table 8: NMSE for each degree of freedom obtained when comparing network predictions against the ground truth in E-III.
Layer
5 th DOF
15 th DOF
35 th DOF
65 th DOF
75 th DOF
A1
12.4
23.0
09.5
08.2
11.4
A2
31.3
15.0
24.3
09.4
08.0
Table 9: Spiking activity (%) for the two layers (A1 and A2) of the branch network in CoNBONet (Example E-III).
DOF
Model
AvgCov
MinCov
MaxCov
<95 / ≥95 (%)
5 th
BONet
85.91
76.36
100.00
86 / 14.00
CoBONet
98.66
97.54
100.00
0 / 100.00
NBONet
82.72
54.00
99.80
88 / 12.00
CoNBONet
99.02
97.62
99.72
0 / 100.00
15 th
BONet
89.97
81.18
99.96
73 / 27.00
CoBONet
98.95
98.12
99.96
0 / 100.00
Table 10: Coverage provided by the confidence intervals generated using various network in example E-III.
Figure 9: PoF obtained using FTTF analysis at 76 th DOF in E-III. The PoF is computed corresponding to different threshold vales.
The Hong Kong University of Science and Technology (Guangzhou), Guangzhou, China · The Hong Kong University of Science and Technology, Hong Kong SAR, China