Active Sequential Posterior Estimation for Sample-Efficient Simulation-Based Inference

Authors: Sam Griesemer, Defu Cao, Zijun Cui, Carolina Osorio, Yan Liu

NeurIPS 2024 | Conference PDF | Archive PDF | Plain Text | LLM Run Details

Reproducibility Variable Result LLM Response
Research Type Experimental We further demonstrate the effectiveness of the proposed method in the travel demand calibration setting, a high-dimensional inverse problem commonly requiring computationally expensive traffic simulators. Our method outperforms well-tuned benchmarks and state-of-the-art posterior estimation methods on a large-scale real-world traffic network, as well as demonstrates a performance advantage over non-active counterparts on a suite of SBI benchmark environments.
Researcher Affiliation Collaboration Sam Griesemer1 Defu Cao1 Zijun Cui1,2 Carolina Osorio3,4 Yan Liu1 1USC 2MSU 3Google Research 4HEC Montréal
Pseudocode Yes Algorithm 1 Active Sequential Neural Posterior Estimation (ASNPE)
Open Source Code Yes Available at https://github.com/samgriesemer/seqinf.
Open Datasets Yes We conducted a case study on the large-scale regional Munich network seen in [37].
Dataset Splits No The paper does not explicitly define training, validation, and test splits (e.g., 70/15/15%) for a fixed dataset in the conventional machine learning sense, instead focusing on sequential data collection and model updates.
Hardware Specification Yes To run experiments, we employed our own hardward locally, which is an linux-based machine running an Intel(R) Core(TM) i9-10900X CPU @ 3.70GHz 64GB memory, and NVIDIA Ge Force RTX 2080 Ti.
Software Dependencies No The paper mentions 'Python 3.11', and the use of 'sbi[44]' and 'sbibm[28] Python packages', as well as 'SUMO [26]'. However, it does not provide specific version numbers for all of these key software components (e.g., sbi, sbibm, or underlying deep learning frameworks like PyTorch/TensorFlow if used by the NDE), which are crucial for full reproducibility.
Experiment Setup Yes In the SNPE loop: total number of rounds R (4 in reported experiments), round-wise sample size N (between 256-512), round-wise selection size B (32 in reported experiments). Neural Density Estimator (NDE) model: our model architecture (used for both SNPE and ASNPE) is a masked autoregressive flow with 5 transform layers, each with masked feedforward blocks containing 50 hidden units, and trained with a (consistent) MC-dropout setting of 0.25. When collecting distributional estimates as described in Eq 4, we used 100 weight samples ϕ p(ϕ|D) (as generally recommended in [21]).