New method recovers signals from saturated data using linear loss and nonconvex penalties.
problem Signal recovery from saturated measurements with sign information loss.
method Linear loss and nonconvex penalties (e.g., minimax concave penalty, sorted ℓ1 norm).
result Estimation error is bounded and recovery performance improved.
New method improves signal reconstruction with nonconvex penalties and parameter control.
problem Reconstructing sparse signals with nonconvex penalties and nonconvexity control.
method Introduces nonconvex penalties (SCAD, MCP) with nonconvexity parameters and controls them to guide AMP trajectory.
result Achieves perfect reconstruction for relatively dense signals with small nonconvexity parameters.
Solves reinforcement learning tasks by guiding policies with a penalty signal.
problem Learning policies that exploit reward loopholes and misspecifications.
method Multi-timescale approach using a penalty signal for constraint satisfaction.
result Proves the convergence of Reward Constrained Policy Optimization (RCPO).
Two new methods improve block-sparse signal recovery from noisy data.
problem Recovering block-sparse signals with unknown partitions.
method LogLOP-l2/l1 and AdaLOP-l2/l1 methods using log-sum penalty and MCP.
result Our methods outperform existing techniques in estimation accuracy.
Lap-VARD algorithm improves signal reconstruction in tomography.
problem Signal reconstruction in tomography with sparsity constraint.
method Laplacian prior and automatic relevance determination framework.
result Optimized Laplacian prior enhances balance between sparsity and accuracy.
One-bit measurements widely exist in the real world, and they can be used to recover sparse signals. This task is known as the problem of learning halfspaces in learning theory and one-bit compressive sensing (1bit-CS) in signal processing. In this paper, we propose novel algorithms based on both convex and nonconvex s…
Adaptive multi-penalty regularization for sparse signal recovery.
problem Sparse signal recovery in multi-parameter settings.
method Adaptive parameter choice based on a generalized Lasso path.
result Data-adaptive regularization parameters for correct support recovery.
Survey on nonconvex penalties for sparse and low-rank recovery in various fields.
problem Achieving sparsity and low-rankness in signal processing, statistics, and machine learning.
method Analysis of nonconvex penalties and their applications.
result Nonconvex penalties can significantly improve performance in various applications.
Unified theory for optimal execution through signal-adaptive quotes in limit order books.
problem Optimal execution in limit order books with signal-dependent factors.
method Develops a unified solution theory for four execution criteria, incorporating signal-dependent drift, price impact, inventory risk, and execution risk.
result Explicit formulas reveal optimal quoting strategies and show signal-dependent drift can significantly affect execution.
Study analyzes sparse linear regression with SCAD penalty under noise, providing theoretical insights and practical tools.
problem Signal reconstruction in sparse linear regression with piecewise continuous nonconvex penalties.
method Theoretical analysis using replica method, development of cross-validation error formula, and annealing procedure.
result The SCAD estimator outperforms ℓ1 in a wide parameter range, with the global minimum of mean square error in the replica symmetric phase. Accelerated gradient method tackles nonconvex penalties in sparse learning.
problem Optimizing nonconvex penalties in sparse statistical learning.
method Generalized Nesterov's accelerated gradient method with hyperparameter optimization.
result Convergence can be made considerably faster with optimal hyperparameters.
A new method for combining multiple data views in supervised learning.
problem Combining multiple data views in supervised learning, especially in biology and medicine.
method Cooperative learning combines squared error loss with an agreement penalty to encourage predictions from different data views to agree.
result Cooperative learning achieves higher predictive accuracy on simulated and real multiomics data.
This study improves graph signal denoising for vector-valued data with non-convex penalties.
problem Denoising piecewise smooth graph signals with varying smoothness levels.
method Extended graph trend filtering with non-convex penalties and ADMM algorithm.
result Non-convex penalties outperform convex ones in recovery performance.
Algorithm estimates sparse signals from linear measurements, improving recovery guarantees.
problem Estimating gradient-sparse signals from noisy linear measurements.
method Iterative alpha expansion with proximal descent and geometric penalty decay.
result Global recovery guarantees under cut-restricted isometry property for Gaussian designs.
In sparse Bayesian learning (SBL), Gaussian scale mixtures (GSMs) have been used to model sparsity-inducing priors that realize a class of concave penalty functions for the regression task in real-valued signal models. Motivated by the relative scarcity of formal tools for SBL in complex-valued models, this paper propo…
Unified method for simultaneous denoising and clustering.
problem Clustering noisy signals.
method Sparse convex wavelet clustering with fusion and group-sparse penalties.
result Unified approach that denoises and clusters simultaneously.
The paper establishes prediction bounds for trend filtering with higher order total variation penalties.
problem Estimating signals with jumps of varying orders using total variation regularization.
method Combining oracle inequalities and interpolating vectors to bound effective sparsity.
result The ℓ1-penalty on (k−1)extth order differences allows adaptive estimation for k∈{1,2,3,4}. This paper addresses the problem of sparsity penalized least squares for applications in sparse signal processing, e.g. sparse deconvolution. This paper aims to induce sparsity more strongly than L1 norm regularization, while avoiding non-convex optimization. For this purpose, this paper describes the design and use of…
Sparse reconstruction approaches using the re-weighted l1-penalty have been shown, both empirically and theoretically, to provide a significant improvement in recovering sparse signals in comparison to the l1-relaxation. However, numerical optimization of such penalties involves solving problems with l1-norms in the ob…
The Lasso is a very well known penalized regression model, which adds an L1 penalty with parameter λ1 on the coefficients to the squared error loss function. The Fused Lasso extends this model by also putting an L1 penalty with parameter λ2 on the difference of neighboring coefficients, assuming the…
Method extracts features from signals for classification with explainability.
problem Lack of interpretability in signal classification models.
method Combining scattering transform and multiclass logistic regression with zeroth-order optimization.
result Uncovered the meaning of scattering transform coefficients.
New method solves complex bilevel optimization problems.
problem Challenging bilevel optimization problems in machine learning.
method Penalty-based bilevel gradient descent (PBGD) algorithm.
result PBGD algorithm converges for constrained bilevel problems.
In this article, we discuss various implementation of L1 filtering in order to detect some properties of noisy signals. This filter consists of using a L1 penalty condition in order to obtain the filtered signal composed by a set of straight trends or steps. This penalty condition, which determines the number of breaks…
Study examines insider trading with penalties, finding optimal penalties increase quickly for small orders.
problem Analyzing the impact of penalties on insider trading behavior and market efficiency.
method Formal economic model with penalty functions, existence and uniqueness theorems, and optimization.
result Optimal penalties increase quickly for small orders, signaling extreme events and incorporating information into prices.
New algorithm reduces Q-value overestimation in deep reinforcement learning.
problem Q-value overestimation in deep reinforcement learning for high-dimensional state spaces.
method Adapting information theory concepts, an intrinsic penalty signal is introduced to encourage reduced Q-value estimates.
result Algorithm outperforms other methods in Atari games, demonstrating efficient and robust learning.
High-dimensional data pose challenges in statistical learning and modeling. Sometimes the predictors can be naturally grouped where pursuing the between-group sparsity is desired. Collinearity may occur in real-world high-dimensional applications where the popular l1 technique suffers from both selection inconsisten…
Efficient cross-validation for multi-penalty ridge regression.
problem Optimizing penalties in cross-validation for multi-penalty ridge regression.
method Developed a computationally efficient formula for the multi-penalty, sample-weighted hat-matrix.
result Significant speed-up in cross-validation for ridge regression models.
Study improves understanding of non-differentiable penalties in high-dimensional settings.
problem Theoretical understanding of non-differentiable penalties like generalized LASSO and nuclear norm in high-dimensional settings.
method Proportional high-dimensional regime analysis with finite sample upper bounds on expected squared error.
result LO provides accurate estimation of out-of-sample risk in high-dimensional settings.
Paper designs a penalty for model order selection using information criteria.
problem Selecting the correct model order from a set of candidate models.
method Designs a penalty for the generalized information criterion (GIC) to minimize underestimation.
result Optimal penalty minimizes underestimation while keeping overestimation below a specified level.
A new method for joint noise removal and trend estimation from sparse signals.
problem Jointly removing noise and estimating trends from sparse signals.
method PENDANTSS combines SOOT/SPOQ penalties with BEADS algorithm in a Trust-Region block alternating variable metric forward-backward approach.
result Outperforms comparable methods in deconvolving analytical chemistry signals.
We propose a data-driven algorithm for the maximum a posteriori (MAP) estimation of stochastic processes from noisy observations. The primary statistical properties of the sought signal is specified by the penalty function (i.e., negative logarithm of the prior probability density function). Our alternating direction m…
Piecewise Linear-Quadratic (PLQ) penalties are widely used to develop models in statistical inference, signal processing, and machine learning. Common examples of PLQ penalties include least squares, Huber, Vapnik, 1-norm, and their asymmetric generalizations. Properties of these estimators depend on the choice of pena…
New test improves tree ensemble pruning for better model performance.
problem Lack of robust theoretical justification for penalty terms in tree ensembles.
method Developed a novel hypothesis test for tree ensemble split quality.
result Significant reduction in out-of-sample loss using the new test.
Proposes GAGA algorithm for automatic hyperparameter learning in signal recovery.
problem Difficulty in selecting hyperparameters in traditional signal recovery methods.
method Global Adaptive Generative Adjustment (GAGA) algorithm for automatic hyperparameter learning and signal estimate.
result Consistency of model selection and signal estimate output.
Two sparsity-aware NSAF algorithms improve sparse system identification with lower complexity.
problem Sparse system identification with improved performance and lower complexity.
method Gradient descent method to minimize combined cost function and l1-norm penalty on filter coefficients.
result Proposed algorithms achieve comparable performance with lower computational complexity.
State-space smoothing has found many applications in science and engineering. Under linear and Gaussian assumptions, smoothed estimates can be obtained using efficient recursions, for example Rauch-Tung-Striebel and Mayne-Fraser algorithms. Such schemes are equivalent to linear algebraic techniques that minimize a conv…
New findings show a balance between data fit and complexity in kernel hyperparameters.
problem Overcorrelation due to reparametrization of kernel hyperparameters.
method Reparametrization of kernel hyperparameters and analysis of marginal likelihood.
result Data fit term influences all other kernel hyperparameters, not just the complexity penalty.
Generative diffusion models forecast implied vol surfaces without arbitrage issues.
problem Forecasting arbitrage-free implied volatility surfaces using historical data with path-dependent dynamics.
method Generative diffusion model (DDPM) with conditional training on market variables, including EWMAs and returns. Dynamic penalty scheme based on SNR to enforce arbitrage-free surfaces.
result Superior performance in volatility forecasting compared to existing methods.
New method improves sparse signal reconstruction using 1RSB-AMP.
problem Sparse signal reconstruction with improved accuracy.
method Developed 1RSB-AMP and 1RSB-SE for SCAD penalty minimization.
result 1RSB-AMP achieves improved reconstruction compared to RS-AMP.
Due to advances in sensors, growing large and complex medical image data have the ability to visualize the pathological change in the cellular or even the molecular level or anatomical changes in tissues and organs. As a consequence, the medical images have the potential to enhance diagnosis of disease, prediction of c…
We address the problem of estimating a sparse low-rank matrix from its noisy observation. We propose an objective function consisting of a data-fidelity term and two parameterized non-convex penalty functions. Further, we show how to set the parameters of the non-convex penalty functions, in order to ensure that the ob…
We study the problem of learning a sparse linear regression vector under additional conditions on the structure of its sparsity pattern. This problem is relevant in machine learning, statistics and signal processing. It is well known that a linear regression can benefit from knowledge that the underlying regression vec…
Random forests use randomness to improve model performance in noisy data.
problem Improving model performance in low signal-to-noise ratio settings.
method Demonstrates that randomness in random forests acts as implicit regularization, similar to shrinkage penalties in regularized regression.
result Random forests achieve strong performance by implicitly regularizing model complexity, especially in noisy data.
Proposes a new graph trend filtering model for inhomogeneous graph signals.
problem Estimating piecewise smooth signals over a graph with varying smoothness levels.
method Introduces a l2,0 norm penalized Graph Trend Filtering (GTF) model and two solution methods: spectral decomposition and simulated annealing.
result The GTF model performs better than existing approaches in denoising, support recovery, and semi-supervised classification.
2-level SLOPE improves high-dimensional inference with fewer hyperparameters.
problem High-dimensional linear regression with complex penalty sequences.
method 2-level SLOPE with three hyperparameters, reducing penalty space.
result Sharp trade-off between TPP and FDP, computationally efficient.
AdaTrans adapts to feature and sample transfer in high-dimensional regression.
problem High-dimensional linear regression with more features than samples.
method F-AdaTrans and S-AdaTrans methods using fused-penalties and adaptive weights.
result AdaTrans achieves convergence rates close to oracle estimators and near-minimax optimal rates.
Paper proposes a nonconvex approach for sparse reduced rank regression.
problem Sparse reduced rank regression model estimation problem.
method Formulated as a nonconvex optimization problem with alternating minimization method.
result Nonconvex function leads to better estimation accuracy and efficiency.
Investigates JM for reducing downside risk in market regimes.
problem Mitigating downside risk during market downturns.
method Statistical jump model for identifying market regimes, optimizing penalty for state transitions.
result JM-guided strategies outperform traditional models in reducing risk and enhancing returns.