1 code implementation • 9 Dec 2024 • Yaşar Cahit Yıldırım, Efe Mert Karagözlü, İlter Onat Korkmaz, Çağın Ararat, Cem Tekin
We introduce VOPy, an open-source Python library designed to address black-box vector optimization, where multiple objectives must be optimized simultaneously with respect to a partial order induced by a convex cone.
1 code implementation • 3 Dec 2024 • İlter Onat Korkmaz, Yaşar Cahit Yıldırım, Çağın Ararat, Cem Tekin
VOGP allows users to convey objective preferences through ordering cones while performing efficient sampling by exploiting the smoothness of the objective function, resulting in a more effective optimization process that requires fewer evaluations.
no code implementations • 16 Aug 2024 • Wissam AlAli, Çağın Ararat
We assume that the systemic risk measure is defined using a general aggregation function with some continuity properties and value-at-risk applied as a monetary risk measure.
no code implementations • 23 Jul 2024 • Çağın Ararat, Zachary Feinstein
Risk measures for random vectors have been considered in multi-asset markets with transaction costs and financial networks in the literature.
no code implementations • 14 Jan 2022 • Çağın Ararat, Barış Bilir, Elisa Mastrogiacomo
The notion of convexity index, defined in 1980s for finite-dimensional vector spaces, plays a crucial role in the discussion of decomposable sums.
no code implementations • 23 Oct 2021 • Çağın Ararat, Cem Tekin
We introduce vector optimization problems with stochastic bandit feedback, in which preferences among designs are encoded by a polyhedral ordering cone $C$.
no code implementations • 23 Oct 2021 • Çağın Ararat, Francesco Cesarone, Mustafa Çelebi Pınar, Jacopo Maria Ricci
In this paper, we investigate the features and the performance of the Risk Parity (RP) portfolios using the Mean Absolute Deviation (MAD) as a risk measure.
no code implementations • 29 Aug 2021 • Çağın Ararat, Mücahit Aygün
Motivated by the problem of finding dual representations for quasiconvex systemic risk measures in financial mathematics, we study quasiconvex compositions in an abstract infinite-dimensional setting.
no code implementations • 11 Dec 2020 • Çağın Ararat
We study a static portfolio optimization problem with two risk measures: a principle risk measure in the objective function and a secondary risk measure whose value is controlled in the constraints.
1 code implementation • 24 Jun 2020 • Andi Nika, Kerem Bozgan, Sepehr Elahi, Çağın Ararat, Cem Tekin
We consider the problem of optimizing a vector-valued objective function $\boldsymbol{f}$ sampled from a Gaussian Process (GP) whose index set is a well-behaved, compact metric space $({\cal X}, d)$ of designs.
no code implementations • 14 Dec 2019 • Çağın Ararat, Zachary Feinstein
Scalar dynamic risk measures for univariate positions in continuous time are commonly represented as backward stochastic differential equations.
no code implementations • 25 Mar 2019 • Tahsin Deniz Aktürk, Çağın Ararat
We provide analytical results for a static portfolio optimization problem with two coherent risk measures.
no code implementations • 20 Mar 2019 • Çağın Ararat, Nurtai Meimanjan
Systemic risk is concerned with the instability of a financial system whose members are interdependent in the sense that the failure of a few institutions may trigger a chain of defaults throughout the system.