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- Publications
- Influence

An inexact successive quadratic approximation method for L-1 regularized optimization

- R. Byrd, J. Nocedal, Figen Öztoprak
- Mathematics, Computer Science
- Math. Program.
- 1 June 2016

We study a Newton-like method for the minimization of an objective function $$\phi $$ϕ that is the sum of a smooth function and an $$\ell _1$$ℓ1 regularization term. This method, which is sometimes… Expand

Newton-Like Methods for Sparse Inverse Covariance Estimation

- P. Olsen, Figen Öztoprak, J. Nocedal, S. Rennie
- Computer Science
- NIPS
- 3 December 2012

We propose two classes of second-order optimization methods for solving the sparse inverse covariance estimation problem. The first approach, which we call the Newton-LASSO method, minimizes a… Expand

A family of second-order methods for convex $$\ell _1$$ℓ1-regularized optimization

- R. Byrd, Gillian M. Chin, J. Nocedal, Figen Öztoprak
- Computer Science, Mathematics
- Math. Program.
- 1 September 2016

This paper is concerned with the minimization of an objective that is the sum of a convex function f and an $$\ell _1$$ℓ1 regularization term. Our interest is in active-set methods that incorporate… Expand

Multiagent cooperation for solving global optimization problems: an extendible framework with example cooperation strategies

- Fatma Başak Aydemir, A. Günay, Figen Öztoprak, S. Birbil, P. Yolum
- Computer Science
- J. Glob. Optim.
- 1 October 2013

This paper proposes the use of multiagent cooperation for solving global optimization problems through the introduction of a new multiagent environment, MANGO. The strength of the environment lays in… Expand

A second-order method for convex 1-regularized optimization with active-set prediction

- N. Keskar, J. Nocedal, Figen Öztoprak, A. Wächter
- Computer Science, Mathematics
- Optim. Methods Softw.
- 16 May 2015

We describe an active-set method for the minimization of an objective function φ that is the sum of a smooth convex function f and an -regularization term. A distinctive feature of the method is the… Expand

An interior point method for nonlinear programming with infeasibility detection capabilities

- J. Nocedal, Figen Öztoprak, R. A. Waltz
- Computer Science, Mathematics
- Optim. Methods Softw.
- 1 July 2014

This paper describes an interior point method for nonlinear programming endowed with infeasibility detection capabilities. The method is composed of two phases, a main phase whose goal is to seek… Expand

Solving Global Optimization Problems Using MANGO

- A. Günay, Figen Öztoprak, S. Birbil, P. Yolum
- Computer Science
- KES-AMSTA
- 30 May 2009

Traditional approaches for solving global optimization problems generally rely on a single algorithm. The algorithm may be hybrid or applied in parallel. Contrary to traditional approaches, this… Expand

Parallel algorithms for nonlinear optimization

- Figen Öztoprak
- Computer Science
- 2011

Parallel algorithm design is a very active research topic in optimization as parallel computer architectures have recently become easily accessible. This thesis is about an approach for designing… Expand

- 3
- Open Access

An alternative globalization strategy for unconstrained optimization

- Figen Öztoprak, Ş. İlker Birbil
- Mathematics
- 15 May 2017

Abstract We propose a new globalization strategy that can be used in unconstrained optimization algorithms to support rapid convergence from remote starting points. Our approach is based on using… Expand

MANGO : A MultiAgent ENvironment for Global Optimization

- Lirida Kerçelli, A. Sezer, S. ayse, Figen Öztoprak, P. Yolum, Ş. I. Birbil
- 2008

Hard global optimization problems arise in many areas of engineering. However, solving these problems is a rather difficult task. Most of the existing methods work in isolation and aim at solving… Expand

- 4
- Open Access