16 research outputs found
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Automated McIntosh-Based Classification of Sunspot Groups Using MDI Images
yesThis paper presents a hybrid system for automatic detection and McIntosh-based classification of sunspot groups on SOHO/MDI white-light images using active-region data extracted from SOHO/MDI magnetogram images. After sunspots are detected from MDI white-light images they are grouped/clustered using MDI magnetogram images. By integrating image-processing and neural network techniques, detected sunspot regions are classified automatically according to the McIntosh classification system. Our results show that the automated grouping and classification of sunspots is possible with a high success rate when compared to the existing manually created catalogues. In addition, our system can detect and classify sunspot groups in their early stages, which are usually missed by human observers.EPSR
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Automatic Short-Term Solar Flare Prediction Using Machine Learning and Sunspot Associations.
YesIn this paper, a machine-learning-based system that could provide automated short-term solar flare prediction is presented. This system accepts two sets of inputs: McIntosh classification of sunspot groups and solar cycle data. In order to establish a correlation between solar flares and sunspot groups, the system explores the publicly available solar catalogues from the National Geophysical Data Center to associate sunspots with their corresponding flares based on their timing and NOAA numbers. The McIntosh classification for every relevant sunspot is extracted and converted to a numerical format that is suitable for machine learning algorithms. Using this system we aim to predict whether a certain sunspot class at a certain time is likely to produce a significant flare within six hours time and if so whether this flare is going to be an X or M flare. Machine learning algorithms such as Cascade-Correlation Neural Networks (CCNNs), Support Vector Machines (SVMs) and Radial Basis Function Networks (RBFN) are optimised and then compared to determine the learning algorithm that would provide the best prediction performance. It is concluded that SVMs provide the best performance for predicting whether a McIntosh classified sunspot group is going to flare or not but CCNNs are more capable of predicting the class of the flare to erupt. A hybrid system that combines a SVM and a CCNN is suggested for future use.EPSR
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Automated Solar Activity Prediction: A hybrid computer platform using machine learning and solar imaging for automated prediction of solar flares
yesThe importance of real-time processing of solar data especially for space weather applications is increasing continuously. In this paper, we present an automated hybrid computer platform for the short-term prediction of significant solar flares using SOHO/Michelson Doppler Imager images. This platform is called the Automated Solar Activity Prediction tool (ASAP). This system integrates image processing and machine learning to deliver these predictions. A machine learning-based system is designed to analyze years of sunspot and flare data to create associations that can be represented using computer-based learning rules. An imaging-based real-time system that provides automated detection, grouping, and then classification of recent sunspots based on the McIntosh classification is also created and integrated within this system. The properties of the sunspot regions are extracted automatically by the imaging system and processed using the machine learning rules to generate the real-time predictions. Several performance measurement criteria are used and the results are provided in this paper. Also, quadratic score is used to compare the prediction results of ASAP with NOAA Space Weather Prediction Center (SWPC) between 1999 and 2002, and it is shown that ASAP generates more accurate predictions compared to SWPC.EPSR
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Hybrid imaging and neural networks techniques for processing solar images
YesSolar imaging is currently an active area of research. A fast hybrid system for the automated detection of filaments in solar images is presented in this paper. The system includes three major stages. The central solar region is detected in the first stage using integral projections. Intensity filtering and image enhancement techniques are implemented in the second stage to enhance the quality of detection in the central region. Local detection windows are implemented in the third stage to detect the positions of filaments and to define various sized arrays to contain them. The extracted arrays are fed later to a neural network for verification purposes
3D modeling of magnetic field lines using SOHO/MDI magnetogram images
YesSolar images, along with other observational data, are very important for solar physicists and space weather researchers aiming to understand the way the Sun works and affects Earth. In this study a 3D modelling technique for visualizing solar magnetic field lines using solar images is presented. Photospheric magnetic field footpoints are detected from magnetogram images and using negative and positive magnetic footpoints, dipole pairs are associated according to their proximity. Then, 3D field line models are built using the calculated dipole coordinates, and mapped to detected pairs after coordinate transformations. Final 3D models are compared to extreme ultraviolet images and existing models and the results of visual comparisons are presented
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A multi-wavelength analysis of active regions and sunspots by comparison of automatic detection algorithms
YesThe launch of the Solar Dynamics Observatory (SDO) in early 2010 has provided the solar
physics community with the most detailed view of the Sun to date. However, this presents new
challenges for the analysis of solar data. Currently,
SDO sends over 1 terabyte of data per day back to Earth and methods for fast and reliable analysis are
more important than ever. This article details four algorithms developed separately at the Universities
of Bradford and Glasgow, the
Royal Observatory of Belgium and Trinity College Dublin for the purposes of automated detection of
solar active regions (ARs) and sunspots at different levels of the solar atmosphere
Representation of solar features in 3D for creating visual solar catalogues
YesIn this study a method for 3D representation of active regions and sunspots that are detected from Solar and Heliospheric Observatory/Michelson Doppler Imager magnetogram and continuum images is provided. This is our first attempt to create a visual solar catalogue. Because of the difficulty of providing a full description of data in text based catalogues, it can be more accurate and effective for scientist to search 3D solar feature models and descriptions at the same time in such a visual solar catalogue. This catalogue would improve interpretation of solar images, since it would allow us to extract data embedded in various solar images and visualize it at the same time. In this work, active regions that are detected from magnetogram images and sunspots that are detected from continuum images are represented in 3D coordinates. Also their properties extracted from text based catalogues are represented at the same time in 3D environment. This is the first step for creating a 3D solar feature catalogue where automatically detected solar features will be presented visually together with their properties
Solar flare prediction using advanced feature extraction, machine learning and feature selection
YesNovel machine-learning and feature-selection algorithms have been developed to study: (i)
the flare prediction capability of magnetic feature (MF) properties generated by the recently developed
Solar Monitor Active Region Tracker (SMART); (ii) SMART's MF properties that are most significantly
related to flare occurrence. Spatio-temporal association algorithms are developed to associate MFs
with flares from April 1996 to December 2010 in order to differentiate flaring and non-flaring MFs and
enable the application of machine learning and feature selection algorithms. A machine-learning
algorithm is applied to the associated datasets to determine the flare prediction capability of all 21
SMART MF properties. The prediction performance is assessed using standard forecast verification
measures and compared with the prediction measures of one of the industry's standard technologies
for flare prediction that is also based on machine learning - Automated Solar Activity Prediction (ASAP).
The comparison shows that the combination of SMART MFs with machine learning has the potential to
achieve more accurate flare prediction than ASAP. Feature selection algorithms are then applied to
determine the MF properties that are most related to flare occurrence. It is found that a reduced set of
6 MF properties can achieve a similar degree of prediction accuracy as the full set of 21 SMART MF
properties
Annual Variation in the Diversity, Species Richness and Composition of the Phytoplankton Assemblages in the Izmir Bay (Eastern Aegean)
WOS: 000296070300014In this study, qualitative and quantitative characteristics of phytoplankton community structure and environmental factors which have influences on its distribution and the changes in Izmir Bay (Aegean Sea) were investigated. The water samples were collected seasonally between January 1998 and December 2001 from 3 sampling sites (from surface, -5 m, -10 in and -15 m). During the study period, a total of 115 taxa from three algal classes, Cyanophyceae, Dinophyceae and Bacillariophyceae were determined. Spatio-temporal phytoplankton community composition in the bay was often dominated by dinoflagellates but shift to diatom dominance was observed in some periods, particularly in spring and winter. The Wastewater Treatment Plant (WTP) began to treat domestic and industrial wastes since early 2000. The sampling periods of the study include both before and after the activation of treatment plant. Although WTP is sufficient for removal of nitrogen from the wastes, it is inadequate for removal of phosphate. This is also compatible with the decreasing N/P ratios observed during 2000-2001 in the middle and inner bays. Therefore, the decrease in the ratios caused by treatment plant, affects the species diversity of both dinoflagellat and diatom assemblages. The student's t-tests and the discriminant analyses outcome from different stations and years demonstrate statistically significant variances at a P <= 0.05 probability level. These results indicated that the considerable improvements should be expected in the next years.Izmir Metropolitan MunicipalityBelediyelerThis study has been supported by Izmir Metropolitan Municipality within the framework of the Izmir Bay Marine Research Project. We thank the scientists and the crew of the R/V "Koca Piri Reis" during the cruises