Search Results for author: Suleyman S. Kozat

Found 34 papers, 12 papers with code

Binary Feature Mask Optimization for Feature Selection

1 code implementation23 Jan 2024 Mehmet E. Lorasdagi, Mehmet Y. Turali, Ali T. Koc, Suleyman S. Kozat

However, no study has introduced a training-free framework for a generic ML model to select features while considering the importance of the feature subsets as a whole, instead of focusing on the individual features.

feature selection

AFS-BM: Enhancing Model Performance through Adaptive Feature Selection with Binary Masking

1 code implementation20 Jan 2024 Mehmet Y. Turali, Mehmet E. Lorasdagi, Ali T. Koc, Suleyman S. Kozat

In particular, we do the joint optimization and binary masking to continuously adapt the set of features and model parameters during the training process.

Feature Importance feature selection

Hybrid State Space-based Learning for Sequential Data Prediction with Joint Optimization

no code implementations19 Sep 2023 Mustafa E. Aydın, Arda Fazla, Suleyman S. Kozat

We achieve this by introducing novel state space representations for the base models, which are then combined to provide a full state space representation of the hybrid or the ensemble.

Feature Engineering Time Series

Deep Reinforcement Learning Based Joint Downlink Beamforming and RIS Configuration in RIS-aided MU-MISO Systems Under Hardware Impairments and Imperfect CSI

2 code implementations10 Oct 2022 Baturay Saglam, Doga Gurgunoglu, Suleyman S. Kozat

We introduce a novel deep reinforcement learning (DRL) approach to jointly optimize transmit beamforming and reconfigurable intelligent surface (RIS) phase shifts in a multiuser multiple input single output (MU-MISO) system to maximize the sum downlink rate under the phase-dependent reflection amplitude model.

Deep Intrinsically Motivated Exploration in Continuous Control

2 code implementations1 Oct 2022 Baturay Saglam, Suleyman S. Kozat

In continuous control, exploration is often performed through undirected strategies in which parameters of the networks or selected actions are perturbed by random noise.

Continuous Control reinforcement-learning +1

Actor Prioritized Experience Replay

1 code implementation1 Sep 2022 Baturay Saglam, Furkan B. Mutlu, Dogan C. Cicek, Suleyman S. Kozat

A widely-studied deep reinforcement learning (RL) technique known as Prioritized Experience Replay (PER) allows agents to learn from transitions sampled with non-uniform probability proportional to their temporal-difference (TD) error.

Continuous Control Reinforcement Learning (RL)

Optimal Tracking in Prediction with Expert Advice

no code implementations7 Aug 2022 Hakan Gokcesu, Suleyman S. Kozat

We study the prediction with expert advice setting, where the aim is to produce a decision by combining the decisions generated by a set of experts, e. g., independently running algorithms.

Decision Making

Mitigating Off-Policy Bias in Actor-Critic Methods with One-Step Q-learning: A Novel Correction Approach

1 code implementation1 Aug 2022 Baturay Saglam, Dogan C. Cicek, Furkan B. Mutlu, Suleyman S. Kozat

Compared to on-policy counterparts, off-policy model-free deep reinforcement learning can improve data efficiency by repeatedly using the previously gathered data.

Continuous Control Q-Learning +2

Safe and Robust Experience Sharing for Deterministic Policy Gradient Algorithms

1 code implementation27 Jul 2022 Baturay Saglam, Dogan C. Cicek, Furkan B. Mutlu, Suleyman S. Kozat

Learning in high dimensional continuous tasks is challenging, mainly when the experience replay memory is very limited.

Continuous Control OpenAI Gym +1

A Hybrid Framework for Sequential Data Prediction with End-to-End Optimization

no code implementations25 Mar 2022 Mustafa E. Aydın, Suleyman S. Kozat

We investigate nonlinear prediction in an online setting and introduce a hybrid model that effectively mitigates, via an end-to-end architecture, the need for hand-designed features and manual model selection issues of conventional nonlinear prediction/regression methods.

Decision Making Model Selection +1

AWD3: Dynamic Reduction of the Estimation Bias

no code implementations12 Nov 2021 Dogan C. Cicek, Enes Duran, Baturay Saglam, Kagan Kaya, Furkan B. Mutlu, Suleyman S. Kozat

We show through continuous control environments of OpenAI gym that our algorithm matches or outperforms the state-of-the-art off-policy policy gradient learning algorithms.

Continuous Control OpenAI Gym +1

Off-Policy Correction for Deep Deterministic Policy Gradient Algorithms via Batch Prioritized Experience Replay

no code implementations2 Nov 2021 Dogan C. Cicek, Enes Duran, Baturay Saglam, Furkan B. Mutlu, Suleyman S. Kozat

In addition, experience replay stores the transitions are generated by the previous policies of the agent that may significantly deviate from the most recent policy of the agent.

Computational Efficiency Continuous Control

Estimation Error Correction in Deep Reinforcement Learning for Deterministic Actor-Critic Methods

1 code implementation22 Sep 2021 Baturay Saglam, Enes Duran, Dogan C. Cicek, Furkan B. Mutlu, Suleyman S. Kozat

We show that in deep actor-critic methods that aim to overcome the overestimation bias, if the reinforcement signals received by the agent have a high variance, a significant underestimation bias arises.

Continuous Control OpenAI Gym +3

PySAD: A Streaming Anomaly Detection Framework in Python

1 code implementation5 Sep 2020 Selim F. Yilmaz, Suleyman S. Kozat

PySAD is an open-source python framework for anomaly detection on streaming data.

Anomaly Detection

Multi-Label Sentiment Analysis on 100 Languages with Dynamic Weighting for Label Imbalance

1 code implementation26 Aug 2020 Selim F. Yilmaz, E. Batuhan Kaynak, Aykut Koç, Hamdi Dibeklioğlu, Suleyman S. Kozat

We investigate cross-lingual sentiment analysis, which has attracted significant attention due to its applications in various areas including market research, politics and social sciences.

Object Recognition Sentiment Analysis

Spatio-temporal Sequence Prediction with Point Processes and Self-organizing Decision Trees

no code implementations25 Jun 2020 Oguzhan Karaahmetoglu, Suleyman S. Kozat

We study the spatio-temporal prediction problem and introduce a novel point-process-based prediction algorithm.

Point Processes

A Tree Architecture of LSTM Networks for Sequential Regression with Missing Data

no code implementations22 May 2020 S. Onur Sahin, Suleyman S. Kozat

In our architecture, we employ a variable number of LSTM networks, which use only the existing inputs in the sequence, in a tree-like architecture without any statistical assumptions or imputations on the missing data, unlike all the previous approaches.

regression

Achieving Online Regression Performance of LSTMs with Simple RNNs

no code implementations16 May 2020 N. Mert Vural, Fatih Ilhan, Selim F. Yilmaz, Salih Ergüt, Suleyman S. Kozat

Recurrent Neural Networks (RNNs) are widely used for online regression due to their ability to generalize nonlinear temporal dependencies.

regression

Unsupervised Anomaly Detection via Deep Metric Learning with End-to-End Optimization

1 code implementation12 May 2020 Selim F. Yilmaz, Suleyman S. Kozat

We investigate unsupervised anomaly detection for high-dimensional data and introduce a deep metric learning (DML) based framework.

Metric Learning Unsupervised Anomaly Detection

RNN-based Online Learning: An Efficient First-Order Optimization Algorithm with a Convergence Guarantee

no code implementations7 Mar 2020 N. Mert Vural, Selim F. Yilmaz, Fatih Ilhan, Suleyman S. Kozat

We investigate online nonlinear regression with continually running recurrent neural network networks (RNNs), i. e., RNN-based online learning.

regression

Stability of the Decoupled Extended Kalman Filter Learning Algorithm in LSTM-Based Online Learning

no code implementations25 Nov 2019 Nuri Mert Vural, Fatih Ilhan, Suleyman S. Kozat

We investigate the convergence and stability properties of the decoupled extended Kalman filter learning algorithm (DEKF) within the long-short term memory network (LSTM) based online learning framework.

Minimax Optimal Algorithms for Adversarial Bandit Problem with Multiple Plays

no code implementations25 Nov 2019 N. Mert Vural, Hakan Gokcesu, Kaan Gokcesu, Suleyman S. Kozat

To construct our algorithm, we introduce a new expert advice algorithm for the multiple-play setting.

An Efficient and Effective Second-Order Training Algorithm for LSTM-based Adaptive Learning

1 code implementation22 Oct 2019 N. Mert Vural, Salih Ergüt, Suleyman S. Kozat

We study adaptive (or online) nonlinear regression with Long-Short-Term-Memory (LSTM) based networks, i. e., LSTM-based adaptive learning.

regression

Universal Online Convex Optimization with Minimax Optimal Second-Order Dynamic Regret

no code implementations30 Jun 2019 Hakan Gokcesu, Suleyman S. Kozat

Our approach can compete against all comparator sequences simultaneously (universally) in a minimax optimal manner, i. e. each regret guarantee depends on the respective comparator path variation.

Minimax Optimal Online Stochastic Learning for Sequences of Convex Functions under Sub-Gradient Observation Failures

no code implementations19 Apr 2019 Hakan Gokcesu, Suleyman S. Kozat

We specifically study scenarios where our sub-gradient observations can be noisy or even completely missing in a stochastic manner.

Highly Efficient Hierarchical Online Nonlinear Regression Using Second Order Methods

no code implementations18 Jan 2017 Burak C. Civek, Ibrahim Delibalta, Suleyman S. Kozat

We introduce highly efficient online nonlinear regression algorithms that are suitable for real life applications.

regression Second-order methods

An Asymptotically Optimal Contextual Bandit Algorithm Using Hierarchical Structures

no code implementations5 Dec 2016 Mohammadreza Mohaghegh Neyshabouri, Kaan Gokcesu, Huseyin Ozkan, Suleyman S. Kozat

Therefore, we design our algorithms based on the optimal adaptive combination and asymptotically achieve the performance of the best mapping as well as the best arm selection policy.

Multi-class Classification

Team-Optimal Distributed MMSE Estimation in General and Tree Networks

no code implementations3 Oct 2016 Muhammed O. Sayin, Suleyman S. Kozat, Tamer Başar

Finally, in the numerical examples, we demonstrate the superior performance of the introduced algorithms in the finite-horizon MSE sense due to optimal estimation.

Data Imputation through the Identification of Local Anomalies

no code implementations30 Sep 2014 Huseyin Ozkan, Ozgun S. Pelvan, Suleyman S. Kozat

We introduce a comprehensive and statistical framework in a model free setting for a complete treatment of localized data corruptions due to severe noise sources, e. g., an occluder in the case of a visual recording.

Imputation

Predicting Nearly As Well As the Optimal Twice Differentiable Regressor

no code implementations23 Jan 2014 N. Denizcan Vanli, Muhammed O. Sayin, Suleyman S. Kozat

We study nonlinear regression of real valued data in an individual sequence manner, where we provide results that are guaranteed to hold without any statistical assumptions.

regression

A Novel Family of Adaptive Filtering Algorithms Based on The Logarithmic Cost

no code implementations26 Nov 2013 Muhammed O. Sayin, N. Denizcan Vanli, Suleyman S. Kozat

We introduce important members of this family of algorithms such as the least mean logarithmic square (LMLS) and least logarithmic absolute difference (LLAD) algorithms that improve the convergence performance of the conventional algorithms.

A Unified Approach to Universal Prediction: Generalized Upper and Lower Bounds

no code implementations25 Nov 2013 N. Denizcan Vanli, Suleyman S. Kozat

We first introduce the lower bounds on this relative performance in the mixture of experts framework, where we show that for any sequential algorithm, there always exists a sequence for which the performance of the sequential algorithm is lower bounded by zero.

Learning Theory

A Comprehensive Approach to Universal Piecewise Nonlinear Regression Based on Trees

no code implementations25 Nov 2013 N. Denizcan Vanli, Suleyman S. Kozat

In this paper, we investigate adaptive nonlinear regression and introduce tree based piecewise linear regression algorithms that are highly efficient and provide significantly improved performance with guaranteed upper bounds in an individual sequence manner.

regression

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