Search Results for author: Azim Ahmadzadeh

Found 11 papers, 3 papers with code

Multiscale Dubuc: A New Similarity Measure for Time Series

1 code implementation15 Nov 2024 Mahsa Khazaei, Azim Ahmadzadeh, Krishna Rukmini Puthucode

In this study, however, we present a different similarity measure that fuses the notion of Dubuc's variation from fractal analysis with the Intersection-over-Union (IoU) measure which is widely used in object recognition (also known as the Jaccard Index).

Dynamic Time Warping Object Recognition +3

Measuring Class-Imbalance Sensitivity of Deterministic Performance Evaluation Metrics

no code implementations20 Jun 2022 Azim Ahmadzadeh, Rafal A. Angryk

In this paper, we introduce an intuitive evaluation framework that quantifies metrics' sensitivity to the class imbalance.

Improving Solar Flare Prediction by Time Series Outlier Detection

no code implementations14 Jun 2022 Junzhi Wen, Md Reazul Islam, Azim Ahmadzadeh, Rafal A. Angryk

While a number of machine-learning methods have been proposed to improve flare prediction, none of them, to the best of our knowledge, have investigated the impact of outliers on the reliability and those models' performance.

Outlier Detection Solar Flare Prediction +2

Feature Selection on a Flare Forecasting Testbed: A Comparative Study of 24 Methods

1 code implementation30 Sep 2021 Atharv Yeoleka, Sagar Patel, Shreejaa Talla, Krishna Rukmini Puthucode, Azim Ahmadzadeh, Viacheslav M. Sadykov, Rafal A. Angryk

We incorporated 24 Feature Subset Selection (FSS) algorithms, including multivariate and univariate, supervised and unsupervised, wrappers and filters.

feature selection Time Series +1

Towards Synthetic Multivariate Time Series Generation for Flare Forecasting

no code implementations16 May 2021 Yang Chen, Dustin J. Kempton, Azim Ahmadzadeh, Rafal A. Angryk

We utilize a flare forecasting benchmark dataset, named SWAN-SF, and design two verification methods to both quantitatively and qualitatively evaluate the similarity between the generated minority and the ground-truth samples.

Generative Adversarial Network Synthetic Data Generation +3

How to Train Your Flare Prediction Model: Revisiting Robust Sampling of Rare Events

no code implementations12 Mar 2021 Azim Ahmadzadeh, Berkay Aydin, Manolis K. Georgoulis, Dustin J. Kempton, Sushant S. Mahajan, Rafal A. Angryk

We present a case study of solar flare forecasting by means of metadata feature time series, by treating it as a prominent class-imbalance and temporally coherent problem.

Time Series Time Series Forecasting

Challenges with Extreme Class-Imbalance and Temporal Coherence: A Study on Solar Flare Data

no code implementations20 Nov 2019 Azim Ahmadzadeh, Maxwell Hostetter, Berkay Aydin, Manolis K. Georgoulis, Dustin J. Kempton, Sushant S. Mahajan, Rafal A. Angryk

This is in particular prevalent in interdisciplinary research where the theoretical aspects are sometimes overshadowed by the challenges of the application.

Time Series Time Series Analysis

Toward Filament Segmentation Using Deep Neural Networks

no code implementations20 Nov 2019 Azim Ahmadzadeh, Sushant S. Mahajan, Dustin J. Kempton, Rafal A. Angryk, Shihao Ji

Despite the known challenges in the identification and characterization of filaments by the existing module, which in turn are inherited into any other module that intends to learn from such outputs, Mask R-CNN shows promising results.

A Curated Image Parameter Dataset from Solar Dynamics Observatory Mission

no code implementations3 Jun 2019 Azim Ahmadzadeh, Dustin J. Kempton, Rafal A. Angryk

We provide a large image parameter dataset extracted from the Solar Dynamics Observatory (SDO) mission's AIA instrument, for the period of January 2011 through the current date, with the cadence of six minutes, for nine wavelength channels.

Content-Based Image Retrieval Dimensionality Reduction +2

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