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High-dimensional sparse modeling via regularization provides a powerful tool for analyzing large-scale data sets and obtaining meaningful, interpretable models. The use of nonconvex penalty functions shows advantage in selecting important…

Methodology · Statistics 2016-05-12 Zemin Zheng , Yingying Fan , Jinchi Lv

This paper generalizes results concerning strong convexity of two-stage mean-risk models with linear recourse to distortion risk measures. Introducing the concept of (restricted) partial strong convexity, we conduct an in-depth analysis of…

Optimization and Control · Mathematics 2018-12-20 Matthias Claus , Kai Spürkel

A general class of nonconvex optimization problems is considered, where the penalty is the composition of a linear operator with a nonsmooth nonconvex mapping, which is concave on the positive real line. The necessary optimality condition…

Optimization and Control · Mathematics 2018-04-23 Daria Ghilli , Karl Kunisch

We address high-dimensional zero-one random parameters in two-stage convex conic optimization problems. Such parameters typically represent failures of network elements and constitute rare, high-impact random events in several applications.…

Optimization and Control · Mathematics 2021-07-20 Anirudh Subramanyam , Mohamed El Tonbari , Kibaek Kim

This paper considers stochastic optimization problems with weakly convex objective and constraint functions. We propose Prox-PEP, a proximal method equipped with quadratic subproblems. To handle nonlinear equality constraints, we employ an…

Optimization and Control · Mathematics 2026-05-11 Lixin Tang , Xingyu Wang , Liwei Zhang

The advancement of artificial intelligence has cast a new light on the development of optimization algorithm. This paper proposes to learn a two-phase (including a minimization phase and an escaping phase) global optimization algorithm for…

Machine Learning · Computer Science 2020-03-11 Haotian Zhang , Jianyong Sun , Zongben Xu

Cox's proportional hazards model is one of the most popular statistical models to evaluate associations of exposure with a censored failure time outcome. When confounding factors are not fully observed, the exposure hazard ratio estimated…

Methodology · Statistics 2022-01-04 Linbo Wang , Eric Tchetgen Tchetgen , Torben Martinussen , Stijn Vansteelandt

In this paper we address the challenges posed by non-proportional hazards and informative censoring, offering a path toward more meaningful causal inference conclusions. We start from the marginal structural Cox model, which has been widely…

Methodology · Statistics 2023-11-15 Jiyu Luo , Denise Rava , Jelena Bradic , Ronghui Xu

We consider the problem of estimating the possibly non-convex cost of an agent by observing its interactions with a nonlinear, non-stationary and stochastic environment. For this inverse problem, we give a result that allows to estimate the…

Optimization and Control · Mathematics 2023-07-24 Émiland Garrabé , Hozefa Jesawada , Carmen Del Vecchio , Giovanni Russo

Sparse reduced rank regression is an essential statistical learning method. In the contemporary literature, estimation is typically formulated as a nonconvex optimization that often yields to a local optimum in numerical computation. Yet,…

Methodology · Statistics 2022-12-06 Canhong Wen , Ruipeng Dong , Xueqin Wang , Weiyu Li , Heping Zhang

This work presents a unified framework that combines global approximations with locally built models to handle challenging nonconvex and nonsmooth composite optimization problems, including cases involving extended real-valued functions. We…

Optimization and Control · Mathematics 2026-02-19 Welington de Oliveira , Johannes O. Royset

Non-convex optimization plays a key role in a growing number of machine learning applications. This motivates the identification of specialized structure that enables sharper theoretical analysis. One such identified structure is…

Optimization and Control · Mathematics 2023-06-06 Qiang Fu , Dongchu Xu , Ashia Wilson

In this paper, we discuss the ambiguous chance constrained based portfolio optimization problems, in which the perturbations associated with the input parameters are stochastic in nature, but their distributions are not known precisely. We…

Optimization and Control · Mathematics 2023-11-09 Pulak Swain , Akshay Kumar Ojha

This paper is concerned with solving nonconvex learning problems with folded concave penalty. Despite that their global solutions entail desirable statistical properties, they lack optimization techniques that guarantee global optimality in…

Statistics Theory · Mathematics 2016-03-25 Hongcheng Liu , Tao Yao , Runze Li

Frailty models are often the model of choice for heterogeneous survival data. A frailty model contains both random effects and fixed effects, with the random effects accommodating for the correlation in the data. Different estimation…

Methodology · Statistics 2019-09-17 Oodally Ajmal , Luc Duchateau , Estelle Kuhn

We establish upper bounds for the expected excess risk of models trained by proper iterative algorithms which approximate the local minima. Unlike the results built upon the strong globally strongly convexity or global growth conditions…

Machine Learning · Computer Science 2022-10-11 Mingyang Yi , Ruoyu Wang , Zhi-Ming Ma

This paper proposes novel algorithm for non-convex multimodal constrained optimisation problems. It is based on sequential solving restrictions of problem to sections of feasible set by random subspaces (in general, manifolds) of low…

Optimization and Control · Mathematics 2023-03-28 Dmitry A. Pasechnyuk , Alexander Gornov

We revisit Cox's proportional hazard models and LASSO in the aim of improving feature selection in survival analysis. Unlike traditional methods relying on cross-validation or BIC, the penalty parameter $\lambda$ is directly tuned for…

Machine Learning · Statistics 2025-10-23 Maxime van Cutsem , Sylvain Sardy

We consider the classic Kelly gambling problem with general distribution of outcomes, and an additional risk constraint that limits the probability of a drawdown of wealth to a given undesirable level. We develop a bound on the drawdown…

Portfolio Management · Quantitative Finance 2016-03-22 Enzo Busseti , Ernest K. Ryu , Stephen Boyd

In this paper, we propose new sequential randomized algorithms for convex optimization problems in the presence of uncertainty. A rigorous analysis of the theoretical properties of the solutions obtained by these algorithms, for full…

Systems and Control · Computer Science 2016-11-17 Mohammadreza Chamanbaz , Fabrizio Dabbene , Roberto Tempo , Venkatakrishnan Venkataramanan , Qing-Guo Wang
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