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You searched for subject:(Solar imaging techniques). Showing records 1 – 3 of 3 total matches.

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University of Bradford

1. Atoum, Ibrahim Ali Ahmad. The development of automatic and solar imaging techniques for the accurate detection, merging, verification and tracking of solar filaments.

Degree: PhD, 2012, University of Bradford

Based on a study of existing solar filament and tracking methods, a fully automated solar filament detection and tracking method is presented. An adaptive thresholding technique is used in a segmentation phase to identify candidate filament pixels. This phase is followed by retrieving the actual filament area from a region grown filament by using statistical parameters and morphological operations. This detection technique gives the opportunity to develop an accurate spine extraction algorithm. Features including separation distance, orientation and average intensities are extracted and fed to a Neural Network (NN) classifier to merge broken filament components. Finally, the results for two consecutive images are compared to detect filament disappearance events, taking advantage of the maps resulting from converting solar images to Heliographic Carrington co-ordinates. The study has demonstrated the novelty of the algorithms developed in terms of them now all being fully automated; significantly the algorithms do not require any empirical values to be used whatsoever unlike previous techniques. This combination of features gives the opportunity for these methods to work in real-time. Comparisons with other researchers shows that the present algorithms represent the filaments more accurately and evaluate computationally faster - which could lead to a more precise tracking practice in real-time. An additional development phase developed in this dissertation in the process of detecting solar filaments is the detection of filament disappearances. Some filaments and prominences end their life with eruptions. When this occurs, they disappear from the surface of the Sun within a few hours. Such events are known as disappearing filaments and it is thought that they are associated with coronal mass ejections (CMEs). Filament disappearances are generally monitored by observing and analysing successive solar H-alpha images. After filament regions are obtained from individual H-alpha images, a NN classifier is used to categorize the detected filaments as Disappeared Filaments (DFs) or Miss-Detected Filaments (MDFs). Features such as Area, Length, Mean, Standard Deviation, Skewness and Kurtosis are extracted and fed to this neural network which achieves a confidence level of at least 80%. Comparing the results with other researchers shows high divergence between the results. The NN method shows better convergence with the results of the National Geophysical Data Centre (NGDC) than the results of the others researchers.

Subjects/Keywords: 523.7; Solar imaging techniques; Solar filaments; Tracking; Detection; Automation; Verification

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Atoum, I. A. A. (2012). The development of automatic and solar imaging techniques for the accurate detection, merging, verification and tracking of solar filaments. (Doctoral Dissertation). University of Bradford. Retrieved from http://hdl.handle.net/10454/5774

Chicago Manual of Style (16th Edition):

Atoum, Ibrahim Ali Ahmad. “The development of automatic and solar imaging techniques for the accurate detection, merging, verification and tracking of solar filaments.” 2012. Doctoral Dissertation, University of Bradford. Accessed October 17, 2019. http://hdl.handle.net/10454/5774.

MLA Handbook (7th Edition):

Atoum, Ibrahim Ali Ahmad. “The development of automatic and solar imaging techniques for the accurate detection, merging, verification and tracking of solar filaments.” 2012. Web. 17 Oct 2019.

Vancouver:

Atoum IAA. The development of automatic and solar imaging techniques for the accurate detection, merging, verification and tracking of solar filaments. [Internet] [Doctoral dissertation]. University of Bradford; 2012. [cited 2019 Oct 17]. Available from: http://hdl.handle.net/10454/5774.

Council of Science Editors:

Atoum IAA. The development of automatic and solar imaging techniques for the accurate detection, merging, verification and tracking of solar filaments. [Doctoral Dissertation]. University of Bradford; 2012. Available from: http://hdl.handle.net/10454/5774


Montana State University

2. Lundberg, Steven Kenneth. Synthetic x-ray imager for solar plasma loops.

Degree: College of Engineering, 1998, Montana State University

Subjects/Keywords: Solar wind.; Magnetic fields.; Imaging systems.; Image processing Digital techniques.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Lundberg, S. K. (1998). Synthetic x-ray imager for solar plasma loops. (Thesis). Montana State University. Retrieved from https://scholarworks.montana.edu/xmlui/handle/1/7700

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Lundberg, Steven Kenneth. “Synthetic x-ray imager for solar plasma loops.” 1998. Thesis, Montana State University. Accessed October 17, 2019. https://scholarworks.montana.edu/xmlui/handle/1/7700.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Lundberg, Steven Kenneth. “Synthetic x-ray imager for solar plasma loops.” 1998. Web. 17 Oct 2019.

Vancouver:

Lundberg SK. Synthetic x-ray imager for solar plasma loops. [Internet] [Thesis]. Montana State University; 1998. [cited 2019 Oct 17]. Available from: https://scholarworks.montana.edu/xmlui/handle/1/7700.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Lundberg SK. Synthetic x-ray imager for solar plasma loops. [Thesis]. Montana State University; 1998. Available from: https://scholarworks.montana.edu/xmlui/handle/1/7700

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Freie Universität Berlin

3. Barkschat, Axel. Investigation of interfaces characterized by metal-centered electron transfer using electrochemical imaging techniques.

Degree: 2004, Freie Universität Berlin

In order to obtain a deeper insight into the mechanisms of operation, the degradation of materials and the possibilities of chemical modification of solar materials still under development, a microscopic photocurrent-mapping technique was used and further developed. For these measurements, samples were selected for their importance in progressing photovoltaic research, and a new improved microscopic set-up (SMSC: scanning microscope for semiconductor characterization) for measurements under local illumination by a tiny laser spot was constructed. The maximum resolution for measurements in electrolytes was 1┬Ám. Surfaces of semiconducting, layer-type sulfides and selenides of tungsten and molybdenum, WS2, WSe2, MoS2 and MoSe2 usually exhibit an anisotropic distribution of photoacivity. By comparison with optical micrographs it was seen that this is due to charge carrier recombination at surface states in the vicinity of cracks or broken edges. At these locations, crystal faces perpendicular to the van der Waals plane with dangling bonds exist. Locally resolved images of the quantum efficiency on as-grown crystallite surfaces of the above materials demonstrate the recombination of photogenerated charge carriers at steps. By chemical surface treatment with Tween80, a polyethoxysorbitaneoleate, and ethylenediaminetetraacetic acid, the photoacitivity could be enhanced. An up to eightfold increase of the locally measured photocurrent was observed, especially in surface areas of previously low photoactivity. In search for samples with isotropic photoactivity stretched out over wider surface areas, a large number of differently prepared samples of the above layer-type semiconductors were examined by the use of the SMSC. Under this point of view, the most promising materials appeared to be polycrystalline films and layers of MoS2 and WS2 obtained from sulphurized molybdenum and tungsten sheets. The latter layers displayed a well expressed texture, as was found out by x-ray diffractometry. In experiments with dye-sensitized solar cells based on TiO2 and sensitized with Ru535-dye, mechanisms of degradation were in the focus of interest. In some cases the complete dissolution of the platinization of the back- contact was observed, which occured only under illumination and only in the presence of air (possibly oxygen). Under longterm-illuminination through round masks, the photodegradation in the illuminated areas and the degradation of the electrolyte could be examined separately. For these cells effects of dissolving platinization could be excluded. If a neutral filter with linearly decreasing optical density was used in the longterm-illumination experiment, a decrease of the photocurrent proportional to the intensity of the incoming light was observed. The photodegradation is assumed to result from instability of the semiconductor-sensitizer-system. In HPLC-analytical investigations a large number of different fractions of possible products were found. This result indicates a reaction of the Ru535-dye,… Advisors/Committee Members: n (gender), Prof. Dr. H. Tributsch (firstReferee), Prof. Dr. J. K. Dohrmann (furtherReferee).

Subjects/Keywords: imaging techniques; electrochemistry; layered semiconductor; dye-sensitized cell; CIS cell; solar cell; 500 Naturwissenschaften und Mathematik::540 Chemie::540 Chemie und zugeordnete Wissenschaften

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Barkschat, A. (2004). Investigation of interfaces characterized by metal-centered electron transfer using electrochemical imaging techniques. (Thesis). Freie Universität Berlin. Retrieved from http://dx.doi.org/10.17169/refubium-6220

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Barkschat, Axel. “Investigation of interfaces characterized by metal-centered electron transfer using electrochemical imaging techniques.” 2004. Thesis, Freie Universität Berlin. Accessed October 17, 2019. http://dx.doi.org/10.17169/refubium-6220.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Barkschat, Axel. “Investigation of interfaces characterized by metal-centered electron transfer using electrochemical imaging techniques.” 2004. Web. 17 Oct 2019.

Vancouver:

Barkschat A. Investigation of interfaces characterized by metal-centered electron transfer using electrochemical imaging techniques. [Internet] [Thesis]. Freie Universität Berlin; 2004. [cited 2019 Oct 17]. Available from: http://dx.doi.org/10.17169/refubium-6220.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Barkschat A. Investigation of interfaces characterized by metal-centered electron transfer using electrochemical imaging techniques. [Thesis]. Freie Universität Berlin; 2004. Available from: http://dx.doi.org/10.17169/refubium-6220

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.