English
Related papers

Related papers: Haar wavelets as a tool for the statistical charac…

200 papers

The ability to automatically and robustly self-verify periodicity present in time-series astronomical data is becoming more important as data sets rapidly increase in size. The age of large astronomical surveys has rendered manual…

Instrumentation and Methods for Astrophysics · Physics 2024-06-14 Niall Miller , Philip Lucas , Yi Sun , Zhen Guo , Calum Morris , William Cooper

The GHM multi-level discrete wavelet transform is proposed as preprocessing for image super resolution with convolutional neural networks. Previous works perform analysis with the Haar wavelet only. In this work, 37 single-level wavelets…

Image and Video Processing · Electrical Eng. & Systems 2022-04-19 Ben Lowe , Hadi Salman , Justin Zhan

In this paper, we propose to improve image decomposition algorithms in the case of noisy images. In \cite{gilles1,aujoluvw}, the authors propose to separate structures, textures and noise from an image. Unfortunately, the use of separable…

Image and Video Processing · Electrical Eng. & Systems 2024-11-12 Jerome Gilles

The first step when investigating time varying data is the detection of any reliable changes in star brightness. This step is crucial to decreasing the processing time by reducing the number of sources processed in later, slower steps.…

Instrumentation and Methods for Astrophysics · Physics 2016-01-27 C. E. Ferreira Lopes , N. J. G. Cross

Over the last decade, signal processing on graphs has become a very active area of research. Specifically, the number of applications, for instance in statistical or deep learning, using frames built from graphs, such as wavelets on graphs,…

Signal Processing · Electrical Eng. & Systems 2023-03-08 Elie Chedemail , Basile de Loynes , Fabien Navarro , Baptiste Olivier

We introduce wavelet-based methodology for estimation of realized variance allowing its measurement in the time-frequency domain. Using smooth wavelets and Maximum Overlap Discrete Wavelet Transform, we allow for the decomposition of the…

Statistical Finance · Quantitative Finance 2015-03-20 Jozef Barunik , Lukas Vacha

Without unrealistic continuity and smoothness assumptions on a distributional density of one dimensional dataset, constructing an authentic possibly-gapped histogram becomes rather complex. The candidate ensemble is described via a…

Methodology · Statistics 2017-11-15 Fushing Hsieh , Tania Roy

We use data from a recent long ASCA observation of the Narrow Line Seyfert 1 Ark 564 to investigate in detail its timing properties. We show that a thorough analysis of the time series, employing techniques not generally applied to AGN…

Astrophysics · Physics 2009-11-07 M. Gliozzi , W. Brinkmann , C. Raeth , I. E. Papadakis , H. Negoro , H. Scheingraber

Wearable computing and context awareness are the focuses of study in the field of artificial intelligence recently. One of the most appealing as well as challenging applications is the Human Activity Recognition (HAR) utilizing smart…

Machine Learning · Computer Science 2018-10-26 Mingtao Dong , Jindong Han

In this paper we consider the reconstruction problem of photoacoustic tomography (PAT) with a flat observation surface. We develop a direct reconstruction method that employs regularization with wavelet sparsity constraints. To that end, we…

Optimization and Control · Mathematics 2017-03-27 Jürgen Frikel , Markus Haltmeier

In a previous paper, we studied two statistical methods used to analyse the variability of active galactic nuclei (AGNs): the C and F statistics. Applying them to observed differential light-curves of 39 AGNs, we found that, even though the…

Astrophysics of Galaxies · Physics 2020-09-02 L. Zibecchi , I. Andruchow , S. A. Cellone , D. D. Carpintero

For partially coherent light fields with random fluctuations, the intensity distributions and statistics have been proven to be more propagation robust compared with coherent light. However, its full potential in practical applications has…

Optics · Physics 2023-03-30 Xingyuan Lu , Zhuoyi Wang , Qiwen Zhan , Yangjian Cai , Chengliang Zhao

For the multi-resolution of wavelet transform, it used to filter the complex gamma Spectrum, the fluctuation is filtered, while the detector resolution is still kept well, which has been demonstrated as a new, promising technique for gamma…

Data Analysis, Statistics and Probability · Physics 2013-09-16 Zhang Jinzhao , Tuo Xianguo

Gamma hadron classification, a central machine learning task in gamma ray astronomy, is conventionally tackled with supervised learning. However, the supervised approach requires annotated training data to be produced in sophisticated and…

Machine Learning · Computer Science 2021-08-31 Lukas Pfahler , Mirko Bunse , Katharina Morik

We study the problem of estimating the time delay between two signals representing delayed, irregularly sampled and noisy versions of the same underlying pattern. We propose and demonstrate an evolutionary algorithm for the (hyper)parameter…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-27 Juan C. Cuevas-Tello , Peter Tino , Somak Raychaudhury , Xin Yao , Markus Harva

We present an automated classification of stars exhibiting periodic, non-periodic and irregular light variations. The Hipparcos catalogue of unsolved variables is employed to complement the training set of periodic variables of Dubath et…

Photonic-chip based TIRF illumination has been used to demonstrate several on-chip optical nanoscopy methods. The sample is illuminated by the evanescent field generated by the electromagnetic wave modes guided inside the optical waveguide.…

Ongoing or upcoming surveys such as Gaia, ZTF, or LSST will observe light-curves of billons or more astronomical sources. This presents new challenges for identifying interesting and important types of variability. Collecting a sufficient…

Instrumentation and Methods for Astrophysics · Physics 2021-09-08 Dae-Won Kim , Doyeob Yeo , Coryn A. L. Bailer-Jones , Giyoung Lee

Anomaly detection and localization in industrial images are essential for automated quality inspection. PaDiM, a prominent method, models the distribution of normal image features extracted by pre-trained Convolutional Neural Networks…

Computer Vision and Pattern Recognition · Computer Science 2025-08-25 Cory Gardner , Byungseok Min , Tae-Hyuk Ahn

There are a variety of industrial products that possess periodic textures or surfaces, such as carbon fiber textiles and display panels. Traditional image-based quality inspection methods for these products require identifying the periodic…

Computer Vision and Pattern Recognition · Computer Science 2024-09-10 Peng Ye , Chengyu Tao , Juan Du