no code implementations • 20 Apr 2023 • Vlad-Raul Constantinescu, Ionel Popescu
We study the geometry of global minima of the loss landscape of overparametrized neural networks.
no code implementations • 3 Sep 2022 • Lucian Beznea, Iulian Cimpean, Oana Lupascu-Stamate, Ionel Popescu, Arghir Zarnescu
As a second goal, we show that the obtained Monte Carlo solver renders { in a constructive way} ReLU deep neural network (DNN) solutions to Poisson problem, whose sizes depend at most polynomialy in the dimension $d$ and in the desired error.
no code implementations • 1 Apr 2022 • Juntao Duan, Ionel Popescu
Minimum-variance portfolio optimizations rely on accurate covariance estimator to obtain optimal portfolios.
no code implementations • 28 Feb 2022 • Marian Petrica, Ionel Popescu
Lastly we use the ensemble to get estimates of the parameters from the real data of Covid19 in Romania and then we illustrate the predictions for different periods of time, from 10 up to 45 days, for the number of deaths.
no code implementations • 1 Jan 2022 • Juntao Duan, Ionel Popescu, Heinrich Matzinger
It is well known the sample covariance has a consistent bias in the spectrum, for example spectrum of Wishart matrix follows the Marchenko-Pastur law.
no code implementations • 1 Dec 2021 • Juntao Duan, Ionel Popescu, Heinrich Matzinger
In particular we prove the distribution of the norm of random vector $X \in \mathbb{R}^n$, whose entries are i. i. d.
no code implementations • 27 Jul 2020 • Marian Petrica, Radu D. Stochitoiu, Marius Leordeanu, Ionel Popescu
The second issue is that there were many factors which affected the evolution of the pandemic.
no code implementations • 23 Jun 2020 • Radu D. Stochiţoiu, Marian Petrica, Traian Rebedea, Ionel Popescu, Marius Leordeanu
More specifically, we want to statistically estimate all the relevant parameters for the new coronavirus COVID-19, such as the reproduction number, fatality rate or length of infectiousness period, based on Romanian patients, as well as be able to predict future outcomes.
no code implementations • 30 May 2020 • Zhibo Dai, Heinrich Matzinger, Ionel Popescu
We study the spectrum reconstruction technique.
no code implementations • 10 Jun 2019 • Jiangning Chen, Zhibo Dai, Juntao Duan, Qianli Hu, Ruilin Li, Heinrich Matzinger, Ionel Popescu, Haoyan Zhai
We propose a new approach to address the text classification problems when learning with partial labels is beneficial.
no code implementations • 8 May 2019 • Jiangning Chen, Zhibo Dai, Juntao Duan, Heinrich Matzinger, Ionel Popescu
Naive Bayes estimator is widely used in text classification problems.
no code implementations • 17 Apr 2019 • Ionel Popescu, Tushar Vaidya
We develop original models to study interacting agents in financial markets and in social networks.