Model Mismatch Trade-offs in LMMSE Estimation
- URL: http://arxiv.org/abs/2105.11964v1
- Date: Tue, 25 May 2021 14:16:45 GMT
- Title: Model Mismatch Trade-offs in LMMSE Estimation
- Abstract summary: We consider a linear minimum mean squared error (LMMSE) estimation framework with model mismatch where the assumed model order is smaller than that of the underlying linear system.
By modelling the regressors of the underlying system as random variables, we analyse the average behaviour of the mean squared error (MSE)
Our results quantify how the MSE depends on the interplay between the number of samples and the number of parameters in the underlying system and in the assumed model.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: We consider a linear minimum mean squared error (LMMSE) estimation framework
with model mismatch where the assumed model order is smaller than that of the
underlying linear system which generates the data used in the estimation
process. By modelling the regressors of the underlying system as random
variables, we analyze the average behaviour of the mean squared error (MSE).
Our results quantify how the MSE depends on the interplay between the number of
samples and the number of parameters in the underlying system and in the
assumed model. In particular, if the number of samples is not sufficiently
large, neither increasing the number of samples nor the assumed model
complexity is sufficient to guarantee a performance improvement.
Related papers
- Reducing Estimation Uncertainty Using Normalizing Flows and Stratification [35.18016233072556]
Current methodologies assume (semi-) distributions such as Gaussian or mixed Gaussian, leading to significant estimation uncertainty if these assumptions do not hold.<n>We propose a flow-based model, integrated with stratified sampling, that leverages a parametrized neural network to offer greater flexibility in modeling unknown data distributions.<n>Our model shows a marked reduction in estimation uncertainty across multiple datasets, including high-dimensional (30 and 128) ones.
arXiv Detail & Related papers (2026-02-11T10:08:10Z) - Ranked from Within: Ranking Large Multimodal Models for Visual Question Answering Without Labels [64.94853276821992]
Large multimodal models (LMMs) are increasingly deployed across diverse applications.
Traditional evaluation methods are largely dataset-centric, relying on fixed, labeled datasets and supervised metrics.
We explore unsupervised model ranking for LMMs by leveraging their uncertainty signals, such as softmax probabilities.
arXiv Detail & Related papers (2024-12-09T13:05:43Z) - Diffusion models for probabilistic programming [56.47577824219207]
Diffusion Model Variational Inference (DMVI) is a novel method for automated approximate inference in probabilistic programming languages (PPLs)
DMVI is easy to implement, allows hassle-free inference in PPLs without the drawbacks of, e.g., variational inference using normalizing flows, and does not make any constraints on the underlying neural network model.
arXiv Detail & Related papers (2023-11-01T12:17:05Z) - The Curious Price of Distributional Robustness in Reinforcement Learning with a Generative Model [71.59406356321101]
This paper investigates model robustness in reinforcement learning (RL) to reduce the sim-to-real gap in practice.<n>We adopt the framework of distributionally robust Markov decision processes (RMDPs), aimed at learning a policy that optimize the worst-case performance when the deployed environment falls within a prescribed uncertainty set around the nominal MDP.
arXiv Detail & Related papers (2023-05-26T02:32:03Z) - Efficient Propagation of Uncertainty via Reordering Monte Carlo Samples [0.7087237546722617]
Uncertainty propagation is a technique to determine model output uncertainties based on the uncertainty in its input variables.
In this work, we investigate the hypothesis that while all samples are useful on average, some samples must be more useful than others.
We introduce a methodology to adaptively reorder MC samples and show how it results in reduction of computational expense of UP processes.
arXiv Detail & Related papers (2023-02-09T21:28:15Z) - Learning from aggregated data with a maximum entropy model [73.63512438583375]
We show how a new model, similar to a logistic regression, may be learned from aggregated data only by approximating the unobserved feature distribution with a maximum entropy hypothesis.
We present empirical evidence on several public datasets that the model learned this way can achieve performances comparable to those of a logistic model trained with the full unaggregated data.
arXiv Detail & Related papers (2022-10-05T09:17:27Z) - Differentiable and Scalable Generative Adversarial Models for Data
Imputation [24.111493826345082]
SCIS consists of two modules, differentiable imputation modeling (DIM) and sample size estimation (SSE)
Experiments upon several real-life large-scale datasets demonstrate that, our proposed system can accelerate the generative adversarial model training by 7.1x.
arXiv Detail & Related papers (2022-01-10T08:03:14Z) - Sampling from Arbitrary Functions via PSD Models [55.41644538483948]
We take a two-step approach by first modeling the probability distribution and then sampling from that model.
We show that these models can approximate a large class of densities concisely using few evaluations, and present a simple algorithm to effectively sample from these models.
arXiv Detail & Related papers (2021-10-20T12:25:22Z) - Model-based metrics: Sample-efficient estimates of predictive model
subpopulation performance [11.994417027132807]
Machine learning models $-$ now commonly developed to screen, diagnose, or predict health conditions are evaluated with a variety of performance metrics.
Subpopulation performance metrics are typically computed using only data from that subgroup, resulting in higher variance estimates for smaller groups.
We propose using an evaluation model $-$ a model that describes the conditional distribution of the predictive model score $-$ to form model-based metric (MBM) estimates.
arXiv Detail & Related papers (2021-04-25T19:06:34Z) - How Faithful is your Synthetic Data? Sample-level Metrics for Evaluating
and Auditing Generative Models [95.8037674226622]
We introduce a 3-dimensional evaluation metric that characterizes the fidelity, diversity and generalization performance of any generative model in a domain-agnostic fashion.
Our metric unifies statistical divergence measures with precision-recall analysis, enabling sample- and distribution-level diagnoses of model fidelity and diversity.
arXiv Detail & Related papers (2021-02-17T18:25:30Z) - Robust Finite Mixture Regression for Heterogeneous Targets [70.19798470463378]
We propose an FMR model that finds sample clusters and jointly models multiple incomplete mixed-type targets simultaneously.
We provide non-asymptotic oracle performance bounds for our model under a high-dimensional learning framework.
The results show that our model can achieve state-of-the-art performance.
arXiv Detail & Related papers (2020-10-12T03:27:07Z) - Revisiting minimum description length complexity in overparameterized
models [38.21167656112762]
We provide an extensive theoretical characterization of MDL-COMP for linear models and kernel methods.
For kernel methods, we show that MDL-COMP informs minimax in-sample error, and can decrease as the dimensionality of the input increases.
We also prove that MDL-COMP bounds the in-sample mean squared error (MSE)
arXiv Detail & Related papers (2020-06-17T22:45:14Z) - Instability, Computational Efficiency and Statistical Accuracy [101.32305022521024]
We develop a framework that yields statistical accuracy based on interplay between the deterministic convergence rate of the algorithm at the population level, and its degree of (instability) when applied to an empirical object based on $n$ samples.
We provide applications of our general results to several concrete classes of models, including Gaussian mixture estimation, non-linear regression models, and informative non-response models.
arXiv Detail & Related papers (2020-05-22T22:30:52Z) - Bayesian System ID: Optimal management of parameter, model, and
measurement uncertainty [0.0]
We evaluate the robustness of a probabilistic formulation of system identification (ID) to sparse, noisy, and indirect data.
We show that the log posterior has improved geometric properties compared with the objective function surfaces of traditional methods.
arXiv Detail & Related papers (2020-03-04T22:48:30Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.