Journal articles: 'Sun-images'

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Häfner, Ralph. "Images of the Black Sun." Revue de littérature comparée 319, no. 3 (2006): 285. http://dx.doi.org/10.3917/rlc.319.0285.

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Kumar, Mohi. "New Detailed Images of the Sun." Eos, Transactions American Geophysical Union 88, no. 14 (April 3, 2007): 159. http://dx.doi.org/10.1029/2007eo140004.

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Greenslade, Thomas B. "Pinhole images of the eclipsing Sun." Physics Teacher 32, no. 6 (September 1994): 347. http://dx.doi.org/10.1119/1.2344030.

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Kriss, Victor. "Measuring pinhole images of the sun." Physics Teacher 34, no. 3 (March 1996): 190–91. http://dx.doi.org/10.1119/1.2344399.

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Kumar, Mohi. "First 3-D images of the Sun." Eos, Transactions American Geophysical Union 88, no. 18 (May 1, 2007): 198. http://dx.doi.org/10.1029/2007eo180003.

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Delouille, V., P. Chainais, and J. F. Hochedez. "Quantifying and containing the curse of high resolution coronal imaging." Annales Geophysicae 26, no. 10 (October 15, 2008): 3169–84. http://dx.doi.org/10.5194/angeo-26-3169-2008.

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Abstract. Future missions such as Solar Orbiter (SO), InterHelioprobe, or Solar Probe aim at approaching the Sun closer than ever before, with on board some high resolution imagers (HRI) having a subsecond cadence and a pixel area of about (80 km)2 at the Sun during perihelion. In order to guarantee their scientific success, it is necessary to evaluate if the photon counts available at these resolution and cadence will provide a sufficient signal-to-noise ratio (SNR). For example, if the inhomogeneities in the Quiet Sun emission prevail at higher resolution, one may hope to locally have more photon counts than in the case of a uniform source. It is relevant to quantify how inhomogeneous the quiet corona will be for a pixel pitch that is about 20 times smaller than in the case of SoHO/EIT, and 5 times smaller than TRACE. We perform a first step in this direction by analyzing and characterizing the spatial intermittency of Quiet Sun images thanks to a multifractal analysis. We identify the parameters that specify the scale-invariance behavior. This identification allows next to select a family of multifractal processes, namely the Compound Poisson Cascades, that can synthesize artificial images having some of the scale-invariance properties observed on the recorded images. The prevalence of self-similarity in Quiet Sun coronal images makes it relevant to study the ratio between the SNR present at SoHO/EIT images and in coarsened images. SoHO/EIT images thus play the role of "high resolution" images, whereas the "low-resolution" coarsened images are rebinned so as to simulate a smaller angular resolution and/or a larger distance to the Sun. For a fixed difference in angular resolution and in Spacecraft-Sun distance, we determine the proportion of pixels having a SNR preserved at high resolution given a particular increase in effective area. If scale-invariance continues to prevail at smaller scales, the conclusion reached with SoHO/EIT images can be transposed to the situation where the resolution is increased from SoHO/EIT to SO/HRI resolution at perihelion.

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Cui, Aijun, Jingyu Zhang, Yi Ma, and Xi Zhang. "A Noise De-Correlation Based Sun Glint Correction Method and Its Effect on Shallow Bathymetry Inversion." Remote Sensing 14, no. 23 (November 25, 2022): 5981. http://dx.doi.org/10.3390/rs14235981.

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Sun glint on the sea surface is the unavoidable noise in optical remote sensing images. Water depth retrieval based on optical remote sensing images is vulnerable to sun glint contamination. Different sun glint correction methods and their possible effects on improving the accuracy of optical remote sensing water depth inversion are worth adequately discussing. Considering the problem that traditional sun glint correction methods are not well applied in shallow or turbid water areas, this paper proposes a sun glint correction method based on noise de-correlation (ND-SGC) which is not affected by the essential characteristics of the water body itself and does not require any auxiliary data. In this paper, we analyze the spectral fidelity of remote sensing images by using ND-SGC method and traditional methods for sun glint correction, and compare the accuracy of bathymetry inversion in different water depth cases and between sun glint pixels and sun glint-free pixels. The experimental results indicated that: (1) the ND-SGC method gives different penalty weights to sun glint pixels and sun glint-free pixels, which meaningfully improves the bathymetric inversion accuracy of sun glint pixels and maintains the bathymetric inversion accuracy of sun glint-free pixels, and is applicable to any water depth range; (2) the ND-SGC method improves bathymetric inversion accuracy in the extremely shallow water region (0–2 m) and shallow water region (2–11 m), while the conventional method suppresses bathymetric inversion accuracy in these two water depth ranges; (3) the ND-SGC method maintains the inversion accuracy of the sun glint-free pixels, while the traditional Hedley method and Goodman method increase the mean relative error (MRE) of these pixels by a maximum of 6.7% and 8.8%, respectively; (4) the ND-SGC method preserves the inherent spectral information of the remote sensing image well, while the spectral fidelity index of the images corrected by traditional methods shows a certain degree of distortion of the image’s spectrum.

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Zeman, Ellen J. "Yohkoh Returns X‐Ray Images of the Sun." Physics Today 45, no. 5 (May 1992): 19. http://dx.doi.org/10.1063/1.2809656.

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Hu, Fangyu, Jie Ma, Bin Fang, Junfeng Ding, and Jun Zhang. "Dehazing for images with sun in the sky." Journal of Electronic Imaging 28, no. 04 (July 22, 2019): 1. http://dx.doi.org/10.1117/1.jei.28.4.043016.

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Gamble, Ryan G. "Tanning and Sun-Protection Portrayal in Magazine Images." Archives of Dermatology 147, no. 8 (August 1, 2011): 983. http://dx.doi.org/10.1001/archdermatol.2011.209.

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Hasan Jawad, Hayder, and Aref Saleh Baron. "Using Sun Fits images for calculation of terrestrial aerosol optical depth (AOD) and Ångström turbidity parameters in countryside of Kufa district." Journal of Kufa-Physics 12, no. 02 (December 10, 2020): 33–38. http://dx.doi.org/10.31257/2018/jkp/2020/120203.

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Since there are no previous studies conducted for calculating Kufa turbidity parameters considering that the urban pollutions is less than that of the Kufa city. For this The prior location of the Faculty of science telescope was chosen to make such observation using a 60 mm solar telescope Coronado of Hα filter equipped with CCD DSI III pro connected to laptop computer . Sun Fits images were captured under a clear sky as well as dusty conditions. Two types of images were classified, one in the clear sky and the other in dusty weather. Matlab code was used to estimate sun intensities in order to calculate aerosol optical depth and Ångström turbidity parameters from sun images. These values are expressing the normality behavior with nearer places in territorial region.

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Hasan Jawad, Hayder, and Aref Saleh Baron. "Using Sun Fits images for calculation of terrestrial aerosol optical depth (AOD) and Ångström turbidity parameters in countryside of Kufa district." Journal of Kufa-Physics 12, no. 02 (December 10, 2020): 33–38. http://dx.doi.org/10.31257/2018/jkp/2020/120203.

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Since there are no previous studies conducted for calculating Kufa turbidity parameters considering that the urban pollutions is less than that of the Kufa city. For this The prior location of the Faculty of science telescope was chosen to make such observation using a 60 mm solar telescope Coronado of Hα filter equipped with CCD DSI III pro connected to laptop computer . Sun Fits images were captured under a clear sky as well as dusty conditions. Two types of images were classified, one in the clear sky and the other in dusty weather. Matlab code was used to estimate sun intensities in order to calculate aerosol optical depth and Ångström turbidity parameters from sun images. These values are expressing the normality behavior with nearer places in territorial region.

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Niccolai, Alessandro, and Alfredo Nespoli. "Sun Position Identification in Sky Images for Nowcasting Application." Forecasting 2, no. 4 (November 16, 2020): 488–504. http://dx.doi.org/10.3390/forecast2040026.

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Very-short-term photovoltaic power forecast, namely nowcasting, is gaining increasing attention to face grid stability issues and to optimize microgrid energy management systems in the presence of large penetration of renewable energy sources. In order to identify local phenomena as sharp ramps in photovoltaic production, whole sky images can be used effectively. The first step in the implementation of new and effective nowcasting algorithms is the identification of Sun positions. In this paper, three different techniques (solar angle-based, image processing-based, and neural network-based techniques) are proposed, described, and compared. These techniques are tested on real images obtained with a camera installed at SolarTechLab at Politecnico di Milano, Milan, Italy. Finally, the three techniques are compared by introducing some performance parameters aiming to evaluate of their reliability, accuracy, and computational effort. The neural network-based technique obtains the best performance: in fact, this method is able to identify accurately the Sun position and to estimate it when the Sun is covered by clouds.

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Heyden, F. J. "Digitizing solar activity from direct images of the sun." Vistas in Astronomy 31 (1988): 99–102. http://dx.doi.org/10.1016/0083-6656(88)90183-3.

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Lindsey, C. "Seismic Images of the Far Side of the Sun." Science 287, no. 5459 (March 10, 2000): 1799–801. http://dx.doi.org/10.1126/science.287.5459.1799.

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Keino, Hiroshi, Takuto Aman, Ryota Furuya, Makiko Nakayama, Annabelle A. Okada, Wataru Sunayama, and Yuji Hatanaka. "Automated Quantitative Analysis of Anterior Segment Inflammation Using Swept-Source Anterior Segment Optical Coherence Tomography: A Pilot Study." Diagnostics 12, no. 11 (November 5, 2022): 2703. http://dx.doi.org/10.3390/diagnostics12112703.

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Background: The aim of this study is to develop an automated evaluation of anterior chamber (AC) cells in uveitis using anterior segment (AS) optical coherence tomography (OCT) images. Methods: We analyzed AS swept-source (SS)-OCT (CASIA 2) images of 31 patients (51 eyes) with uveitis using image analysis software (Python). An automated algorithm was developed to detect cellular spots corresponding to hyper-reflective spots in the AC, and the correlation with Standardization of Uveitis Nomenclature (SUN) grading AC cells score was evaluated. The approximated AC grading value was calculated based on the logarithmic approximation curve between the number of cellular spots and the SUN grading score. Results: Among 51 eyes, cellular spots were automatically segmented in 48 eyes, whereas three eyes (all SUN grading AC cells score: 4+) with severe fibrin formation in the AC were removed by the automated algorithm. The AC cellular spots increased with an increasing SUN grading score (p < 0.001). The 48 eyes were split into training data (26 eyes) and test data (22 eyes). There was a significant correlation between the SUN grading score and the number of cellular spots in 26 eyes (rho: 0.843, p < 0.001). There was a significant correlation between the SUN grading score and the approximated grading value of 22 eyes based on the logarithmic approximation curve (rho: 0.774, p < 0.001). Leave-one-out cross-validation analysis demonstrated a significant correlation between the SUN grading score and the approximated grading value of 48 eyes (rho: 0.748, p < 0.001). Conclusions: This automated anterior AC cell analysis using AS SS-OCT showed a significant correlation with clinical SUN grading scores and provided SUN AC grading values as a continuous variable. Our findings suggest that automated grading of AC cells could improve the accuracy of a quantitative assessment of AC inflammation using AS-OCT images and allow the objective and rapid evaluation of anterior segment inflammation in uveitis. Further investigations on a large scale are required to validate this quantitative measurement of anterior segment inflammation in uveitic eyes.

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Semenikhina, M. V. "Images of the Moon and the Sun in the Poetry of F.H. Thompson." Discourse 9, no. 6 (December 21, 2023): 128–42. http://dx.doi.org/10.32603/2412-8562-2023-9-6-128-142.

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Introduction. The article considers the analysis of metaphorical models describing the Moon and the Sun, two key mythologems in the works of F.H. Thompson, a religious English poet of XIX-XX centuries. The research relevance is connected with the growing interest in the representation of the individual author's worldview in a poetic text and with the fact that the work of F.H. Thompson in Russian philology remains poorly studied.Methodology and sources. The research is based on the conceptual metaphor theory byLakoff and Johnson. The empirical basis of the study was the poems by F.H. Thompson “A Corymbus for Autumn”, “Orient Ode”, “Ode to the Setting Sun”, “The Mistress of Vision”, “An Anthem of Earth”, “Sister Songs”, “From the Night of Forebeing”, “The Hound of Heaven”, “The Song of Hours”, “The Sere of the Leaf”, “The Dead Astronomer”, “Ad Amicam”, “Ad Castitatem”, “Love Declared”, “Of Nature: Laud and Plaint”, “Nocturn”, “Assumpta Maria”, “To a Poet Breaking Silence”, “Arab Love-Song”, “Victorian Ode”.Results and discussion. The analysis revealed that in F.H. Thompson's poetry the images of the Moon and the Sun are contrasted as “passive – active”, “weak – strong”, “chastity – passion”, “cold – heat”, “water – fire”, to a lesser extent “death – life”, “female – male” and “pagan – Christian”. The Sun is a source of life, beauty and poetic inspiration, and, in addition, the movement of the Sun across the sky during the day helps people to understand the story of Christ’s death and resurrection and its sense. The Moon, despite its coldness and passivity, also plays a necessary role in the universe (for example, controlling natural cycles and acting as an intermediary between the Sun and mankind).Conclusion. The images of the Moon and the Sun fit seamlessly into the general system of images of Thompson's poetry, in which the author seeks to create an image of a spiritualized Universe filled with the presence of God. The Sun is the central image of Thompson's poetry, an active character, often likened to Christ; the Moon is more passive and more strongly associated with paganism and death (which, however, does not make its image negative).

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Brajša, R., D. Sudar, A. O. Benz, I. Skokić, M. Bárta, B. De Pontieu, S. Kim, et al. "First analysis of solar structures in 1.21 mm full-disc ALMA image of the Sun." Astronomy & Astrophysics 613 (May 2018): A17. http://dx.doi.org/10.1051/0004-6361/201730656.

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Context. Various solar features can be seen in emission or absorption on maps of the Sun in the millimetre and submillimetre wavelength range. The recently installed Atacama Large Millimetre/submillimetre Array (ALMA) is capable of observing the Sun in that wavelength range with an unprecedented spatial, temporal and spectral resolution. To interpret solar observations with ALMA, the first important step is to compare solar ALMA maps with simultaneous images of the Sun recorded in other spectral ranges. Aims. The first aim of the present work is to identify different structures in the solar atmosphere seen in the optical, infrared, and EUV parts of the spectrum (quiet Sun, active regions, prominences on the disc, magnetic inversion lines, coronal holes and coronal bright points) in a full-disc solar ALMA image. The second aim is to measure the intensities (brightness temperatures) of those structures and to compare them with the corresponding quiet Sun level. Methods. A full-disc solar image at 1.21 mm obtained on December 18, 2015, during a CSV-EOC campaign with ALMA is calibrated and compared with full-disc solar images from the same day in Hα line, in He I 1083 nm line core, and with various SDO images (AIA at 170 nm, 30.4 nm, 21.1 nm, 19.3 nm, and 17.1 nm and HMI magnetogram). The brightness temperatures of various structures are determined by averaging over corresponding regions of interest in the calibrated ALMA image. Results. Positions of the quiet Sun, active regions, prominences on the disc, magnetic inversion lines, coronal holes and coronal bright points are identified in the ALMA image. At the wavelength of 1.21 mm, active regions appear as bright areas (but sunspots are dark), while prominences on the disc and coronal holes are not discernible from the quiet Sun background, despite having slightly less intensity than surrounding quiet Sun regions. Magnetic inversion lines appear as large, elongated dark structures and coronal bright points correspond to ALMA bright points. Conclusions. These observational results are in general agreement with sparse earlier measurements at similar wavelengths. The identification of coronal bright points represents the most important new result. By comparing ALMA and other maps, it was found that the ALMA image was oriented properly and that the procedure of overlaying the ALMA image with other images is accurate at the 5 arcsec level. The potential of ALMA for physics of the solar chromosphere is emphasised.

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Wisse, E., A. Geerts, and R. B. De Zanger. "Routine Digital Processing of Microscope Images." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 1 (August 12, 1990): 550–51. http://dx.doi.org/10.1017/s0424820100181506.

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The slowscan and TV signal of the Philips SEM 505 and the signal of a TV camera attached to a Leitz fluorescent microscope, were digitized by the data acquisition processor of a Masscomp 5520S computer, which is based on a 16.7 MHz 68020 CPU with 10 Mb RAM memory, a graphics processor with two frame buffers for images with 8 bit / 256 grey values, a high definition (HD) monitor (910 × 1150), two hard disks (70 and 663 Mb) and a 60 Mb tape drive. The system is equipped with Imaging Technology video digitizing boards: analog I/O, an ALU, and two memory mapped frame buffers for TV images of the IP 512 series. The Masscomp computer has an ethernet connection to other computers, such as a Vax PDP 11/785, and a Sun 368i with a 327 Mb hard disk and a SCSI interface to an Exabyte 2.3 Gb helical scan tape drive. The operating system for these computers is based on different versions of Unix, such as RTU 4.1 (including NFS) on the acquisition computer, bsd 4.3 for the Vax, and Sun OS 4.0.1 for the Sun (with NFS).

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Pestell, Ben. "The Sun Within: New Solar Myth in Early Novels of Wilson Harris and J.G. Ballard." Culture and Cosmos 24, no. 0102 (October 2020): 81–95. http://dx.doi.org/10.46472/cc.1224.0215.

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Even in our disenchanted age, the Sun remains a potent symbol in mythopoeic literature, and, in very different ways, Wilson Harris and J. G. Ballard each use internalised images of the Sun to construct and narrate their modern mythical landscapes. In Harris’s Palace of the Peacock (1960), the Sun fills the pages with a nebulous and ineffable blinding power. In Ballard’s The Drowned World (1962), the dual image of the physical and the psychological Sun inspires an atavistic pilgrimage. This chapter studies the role of the Sun in each novel, where it serves to inspire a quest for a form of individuation. I argue that Ballard’s Sun is a transcendental engine that drives individual psychic integration, while Harris’s is a gateway into a metaphysical realm of spiritual unity. In each case, the Sun is the focus of a modern mythological method.

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Ortega-Terol, Damian, David Hernandez-Lopez, Rocio Ballesteros, and Diego Gonzalez-Aguilera. "Automatic Hotspot and Sun Glint Detection in UAV Multispectral Images." Sensors 17, no. 10 (October 15, 2017): 2352. http://dx.doi.org/10.3390/s17102352.

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Kakar, Pravin, and N. Sudha. "Verifying Temporal Data in Geotagged Images Via Sun Azimuth Estimation." IEEE Transactions on Information Forensics and Security 7, no. 3 (June 2012): 1029–39. http://dx.doi.org/10.1109/tifs.2012.2188796.

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Babani, Fatbardha, Gabriele Langsdorf, Martin Knapp, Claus Buschmann, and Hartmut K. Lichtenthaler. "UV-A induced fluorescence images in sun and shade leaves." BMC Plant Biology 5, Suppl 1 (2005): S3. http://dx.doi.org/10.1186/1471-2229-5-s1-s3.

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SUN, HAO, SHUXIA WANG, and HOUHUN LI. "Review of the degeerella species group of the genus Nemophora Hoffmannsegg, 1798 (Lepidoptera: Adelidae) from China." Zootaxa 5219, no. 4 (December 12, 2022): 301–38. http://dx.doi.org/10.11646/zootaxa.5219.4.1.

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Twenty-five species of the degeerella species group in the genus Nemophora Hoffmannsegg, 1798 are reviewed from China. Fourteen species are described as new: N. spinatibaltea Sun, Wang et Li, sp. nov., N. parvaprocessa Sun, Wang et Li, sp. nov., N. bifurcifascia Sun, Wang et Li, sp. nov., N. biprocessa Sun, Wang et Li, sp. nov., N. ravidifera Sun, Wang et Li, sp. nov., N. triuga Sun, Wang et Li, sp. nov., N. seorsifascia Sun, Wang et Li, sp. nov., N. borealis Sun, Wang et Li, sp. nov., N. recurvatifera Sun, Wang et Li, sp. nov., N. digitivalva Sun, Wang et Li, sp. nov., N. apiciprocessa Sun, Wang et Li, sp. nov., N. purpuratifera Sun, Wang et Li, sp. nov., N. latirectangula Sun, Wang et Li, sp. nov. and N. gaoligongshana Sun, Wang et Li, sp. nov. Three species, N. chalybeella (Bremer, 1864), N. japonica Stringer, 1930 and N. karafutonis (Matsumura, 1932), are recorded for the first time in China. Images of adults and genitalia of all the species with available specimens in China are given, along with a key to these species. A list of all the species of the degeerella species group in the world is provided.

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Yang, Jun, Qilong Min, Weitao Lu, Ying Ma, Wen Yao, and Tianshu Lu. "An RGB channel operation for removal of the difference of atmospheric scattering and its application on total sky cloud detection." Atmospheric Measurement Techniques 10, no. 3 (March 29, 2017): 1191–201. http://dx.doi.org/10.5194/amt-10-1191-2017.

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Abstract. The inhomogeneous sky background presents a great challenge for accurate cloud recognition from the total-sky images. A channel operation was introduced in this study to produce a new composite channel in which the difference of atmospheric scattering has been removed and a homogeneous sky background can be obtained. Following this, a new cloud detection algorithm was proposed that combined the merits of the differencing and threshold methods, named differencing and threshold combination algorithm (DTCA). Firstly, the channel operation was applied to transform 3-D RGB image to the new channel, then the circumsolar saturated pixels and its circularity were used to judge whether the sun is visible or not in the image. When the sun is obscured, a single threshold can be used to identify cloud pixels. If the sun is visible in the image, the true clear-sky background differencing algorithm is adopted to detect clouds. The qualitative assessment for eight different total-sky images shows the DTCA algorithm obtained satisfactory cloud identification effectiveness for thin clouds and in the circumsolar and near-horizon regions. Quantitative evaluation also shows that the DTCA algorithm achieved the highest cloud recognition precision for five different types of clouds and performed well under both visible sun and blocked sun conditions.

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Takeda, Aki, and Shannon Boland. "How Solar Soft X-Ray Irradiance Is Affected by the Size of Field of View." Astrophysical Journal 960, no. 1 (December 29, 2023): 91. http://dx.doi.org/10.3847/1538-4357/acf9f3.

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Abstract Soft X-ray images of the Sun obtained with multiple broadband filters provide a simple and useful method to calculate averaged coronal temperature and emission measure, from which we can further calculate solar X-ray irradiance in physical units, e.g., watts per square meter. However, X-ray telescopes are often designed for pursuing high spatial resolution, and thus the field of view (FOV) of full-Sun images is often limited over the limb, extending to only ∼1.3 R ⊙. This indicates that the irradiance obtained from the limited FOV may underestimate the true full-Sun irradiance by failing to count the contribution from outside the FOV. This work uses Hinode/X-Ray Telescope (XRT) coronal images observed up to 1.7 R ⊙ to investigate the fraction of irradiance excluded from the FOVs limited in size. The analysis indicates that the irradiance obtained within 1.1 R ⊙, which is used for XRT irradiance study, excludes ∼3.5%/∼7% of irradiance relative to the value within 1.2/1.7 R ⊙, respectively, for the active corona observed in 2022 July. In contrast, the excluded fraction increases to ∼7%/∼13%, respectively, for the minimum corona observed in 2009 August. To further investigate the dependence of exclusion fraction on the Sun’s activity level, we process mission long Yohkoh/Soft X-ray Telescope full-Sun images to compare the irradiance within 1.1 and 0.9 R ⊙ with that obtained from the maximum FOV of 1.2 R ⊙. We confirm that the exclusion fraction is the largest in the period around solar minimum. We also find that the average value of exclusion fraction is slightly but measurably larger in the rising phase than the declining phase of the solar cycle.

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Gage, Ryan, William Leung, James Stanley, Anthony Reeder, Christina Mackay, Tim Chambers, Moira Smith, Michelle Barr, and Louise Signal. "Studying third-parties and environments: New Zealand sun-safety research." Health Promotion International 34, no. 3 (December 15, 2017): 440–46. http://dx.doi.org/10.1093/heapro/dax094.

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Summary Wearable cameras have been used to study health behaviours, but their utility in assessing third-party behaviours and the built environment is uncertain. This paper reports on the feasibility of using wearable cameras for this purpose in a study of sun-protective behaviours and shade availability during school lunch-breaks. The Kids’Cam study provided 168 children (aged 11–13 years), recruited from 16 randomly selected schools in the Wellington region of New Zealand, with wearable cameras. The devices automatically captured images every 7 s from the child’s perspective. Images captured during school lunch-breaks by a random sample of 15 children who took part during terms 4 and 1 (October 2014–April 2015) were selected and assessed for usability. The feasibility of studying third-party sun-protective behaviours and school shade availability was assessed for a subset of 320 images. Of the 3492 eligible lunch-break images, 96.4% were useable; the remainders were excluded due to obstruction, blurriness or unsuitable camera position. Overall, 1278 children and 108 shade structures were observed in the sample images. The use of shade, hats, sleeves, collars and sunglasses could be determined for 97.0%, 77.2%, 74.4%, 47.6% and 54.9% of children, respectively. All shade structures could be classified according to type, and canopy composition could be assessed for 95.4% of structures. Wearable cameras are a feasible tool for assessing sun-safety, particularly shade availability, hat wearing and shade use. This methodology could be used to objectively study other third-party health-related behaviours, and other features of the built environment.

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Long, C. N. "Correcting for Circumsolar and Near-Horizon Errors in Sky Cover Retrievals from Sky Images." Open Atmospheric Science Journal 4, no. 1 (March 26, 2010): 45–52. http://dx.doi.org/10.2174/1874282301004010045.

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Fractional sky cover amounts retrieved from sky imagery are overestimated significantly at times due to occurrences of “whitening” near the sun, and near the horizon for low sun, in the images. This phenomenon occurs due to forward scattering of visible light by aerosols and haze, and the intensity range limitations of the detectors of the cameras used to record the sky images. Our results suggest that when the problem occurs, the magnitude of the overestimate is typically on the order of about 10% to 20% fractional sky cover. To help alleviate this problem, a statistical analysis of the time series of the areas in the image near the sun position and along the horizon centered on the solar azimuth angle has been developed. This statistical analysis requires that images be captured frequently, at least once per minute. For times when the overestimation is detected as occurring, a correction is applied to the retrieved sky cover amounts. When the sky cover amount correction is applied, analysis indicates that the result better matches the actual sky conditions present, as noted by visual inspection of the sky images in question. In addition, frequency-of-occurrence histogram comparisons show that the adjusted results improve the agreement with other methodologies and expectations. Thus, the methodology presented here helps produce more accurate fractional sky cover retrievals.

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Tomanović, Violeta, and Tatjana Cvetkovski. "Visible elements of Covid 19 representations: Aestheticization of the Coronavirus' Black Sun." CM: Communication and Media 17, no. 52 (2022): 157–81. http://dx.doi.org/10.5937/cm17-35355.

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The paper deals with the Covid 19 iconology research, from the beginning of the pandemic at the end of 2019 to the end of 2021. The task of the paper is to determine the way of creating a visible image of the invisible "enemy" and designing stable collective representations. The paper discusses the relationship between black and white images and color images, as well as the relationship between scientific images and stylized, aestheticized and inaccurate coronavirus representations, which enabled the virus, invisible to the eye, to become conceivable globally. The hypothesis of this paper is that mediated reality is transmitted and shaped through visual symbols and coronavirus representations. Although many authors have given their opinion on the uniformity of the coronavirus icon and hence its adaptability in different contexts, the authors of this paper claim that the basic representations of the virus media circulation is the archetypal symbol of the Sun, specifically the Black Sun. The paper also deals with analysis of the frequency of content through the example of the photography that appears 109 times on the official Government of Serbia internet Web page on the Kovid 19 topic, in English, from March 6 2020 to 9 December 2021, and thus, bears different titles and, accordingly, sends different messages. The conclusion of the paper is that the image-icon, the symbol of coronavirus, mainly represents an aestheticized form of real danger and therefore significantly mitigates it, while on the other hand it plays with the archetype of the Sun or Black Sun through its dual nature, i.e. death and transformation.

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Grefenstette, Brian W., Lindsay Glesener, Säm Krucker, Hugh Hudson, Iain G. Hannah, David M. Smith, Julia K. Vogel, et al. "THE FIRST FOCUSED HARD X-RAY IMAGES OF THE SUN WITHNuSTAR." Astrophysical Journal 826, no. 1 (July 18, 2016): 20. http://dx.doi.org/10.3847/0004-637x/826/1/20.

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Overstreet, Brandon T., and Carl J. Legleiter. "Removing sun glint from optical remote sensing images of shallow rivers." Earth Surface Processes and Landforms 42, no. 2 (November 29, 2016): 318–33. http://dx.doi.org/10.1002/esp.4063.

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Asmoro, C. P., and A. R. Achmad. "The analysis of the 2019 annular solar eclipse with simple instruments for developing student worksheet." Journal of Physics: Conference Series 2098, no. 1 (November 1, 2021): 012030. http://dx.doi.org/10.1088/1742-6596/2098/1/012030.

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Abstract The annular solar eclipse occurred when the Earth-Moon-Sun position aligned in the same line where the angular diameter of the moon is smaller than the angular diameter of the sun due to the moon is on the farthest distance with respect to the earth. The event was observed on 26 December 2019 at Siak Regency, Province of Riau, Indonesia. Based on that event observation, the sun is gradually covered by the moon until the peak event where the sun is completely covered and showing “ring of fire”. All stages of eclipse are captured as images from DSLR camera that been attached into telescope with specific filter as well as illumination determination from observation location using lux meter during the event. This study explained how to get the information from solar eclipse images available by using image-processing software namely ImageJ so it can be used as a student worksheet. The plotting of both pixel area-time graph and illumination-time graph of this study shows a similar trend. Therefore, the data acquired in this study is obtained well so it can be used as a student worksheet in the Astronomical Position lecture based on the actual phenomenon with a simple instrument for observation.

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Nindos, A., C. E. Alissandrakis, T. S. Bastian, S. Patsourakos, B. De Pontieu, H. Warren, T. Ayres, et al. "First high-resolution look at the quiet Sun with ALMA at 3mm." Astronomy & Astrophysics 619 (November 2018): L6. http://dx.doi.org/10.1051/0004-6361/201834113.

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We present an overview of high-resolution quiet Sun observations, from disk center to the limb, obtained with the Atacama Large millimeter and sub-millimeter Array (ALMA) at 3 mm. Seven quiet-Sun regions were observed at a resolution of up to 2.5″ by 4.5″. We produced both average and snapshot images by self-calibrating the ALMA visibilities and combining the interferometric images with full-disk solar images. The images show well the chromospheric network, which, based on the unique segregation method we used, is brighter than the average over the fields of view of the observed regions by ∼305 K while the intranetwork is less bright by ∼280 K, with a slight decrease of the network/intranetwork contrast toward the limb. At 3 mm the network is very similar to the 1600 Å images, with somewhat larger size. We detect, for the first time, spicular structures, rising up to 15″ above the limb with a width down to the image resolution and brightness temperature of ∼1800 K above the local background. No trace of spicules, either in emission or absorption, is found on the disk. Our results highlight the potential of ALMA for the study of the quiet chromosphere.

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Lowe, John B., Kevin P. Balanda, Warren R. Stanton, and Amaya Gillespie. "Evaluation of a Three-Year School-Based Intervention to Increase Adolescent Sun Protection." Health Education & Behavior 26, no. 3 (June 1999): 396–408. http://dx.doi.org/10.1177/109019819902600309.

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The efficacy of a school-based intervention was evaluated using a randomized controlled trial in Australia. In consecutive grades (8, 9, and 10), students in the intervention group received components of a program that addressed issues related to the need to protect yourself from the sun, behavioral strategies related to using sunprotective measures, personal and social images of having a tan, the use of sun-safe clothing, and howto change their schools through forms of structural change. Pre-and postintervention measures among junior high school students showed greatest improvement in the intervention group’s knowledge scores and minimal changes in sun protection behavior from Grade 8 to Grade 9, which were not maintained through Grade 10. Results of the study highlight some limitations of school-based interventions for changing sun protection behaviors.

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Li, Fuqin, David L. B. Jupp, Thomas Schroeder, Stephen Sagar, Joshua Sixsmith, and Passang Dorji. "Assessing an Atmospheric Correction Algorithm for Time Series of Satellite-Based Water-Leaving Reflectance Using Match-Up Sites in Australian Coastal Waters." Remote Sensing 13, no. 10 (May 14, 2021): 1927. http://dx.doi.org/10.3390/rs13101927.

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An atmospheric correction algorithm for medium-resolution satellite data over general water surfaces (open/coastal, estuarine and inland waters) has been assessed in Australian coastal waters. In situ measurements at four match-up sites were used with 21 Landsat 8 images acquired between 2014 and 2017. Three aerosol sources (AERONET, MODIS ocean aerosol and climatology) were used to test the impact of the selection of aerosol optical depth (AOD) and Ångström coefficient on the retrieved accuracy. The initial results showed that the satellite-derived water-leaving reflectance can have good agreement with the in situ measurements, provided that the sun glint is handled effectively. Although the AERONET aerosol data performed best, the contemporary satellite-derived aerosol information from MODIS or an aerosol climatology could also be as effective, and should be assessed with further in situ measurements. Two sun glint correction strategies were assessed for their ability to remove the glint bias. The most successful one used the average of two shortwave infrared (SWIR) bands to represent sun glint and subtracted it from each band. Using this sun glint correction method, the mean all-band error of the retrieved water-leaving reflectance at the Lucinda Jetty Coastal Observatory (LJCO) in north east Australia was close to 4% and unbiased over 14 acquisitions. A persistent bias in the other strategy was likely due to the sky radiance being non-uniform for the selected images. In regard to future options for an operational sun glint correction, the simple method may be sufficient for clear skies until a physically based method has been established.

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Valentín, Luis, Manuel Peña-Cruz, Daniela Moctezuma, Cesar Peña-Martínez, Carlos Pineda-Arellano, and Arturo Díaz-Ponce. "Towards the Development of a Low-Cost Irradiance Nowcasting Sky Imager." Applied Sciences 9, no. 6 (March 18, 2019): 1131. http://dx.doi.org/10.3390/app9061131.

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Solar resource assessment is fundamental to reduce the risk in selecting the solar power-plants’ location; also for designing the appropriate solar-energy conversion technology and operating new sources of solar-power generation. Having a reliable methodology for solar irradiance forecasting allows accurately identifying variations in the plant energy production and, as a consequence, determining improvements in energy supply strategies. A new trend for solar resource assessment is based on the analysis of the sky dynamics by processing a set of images of the sky dome. In this paper, a methodology for processing the sky dome images to obtain the position of the Sun is presented; this parameter is relevant to compute the solar irradiance implemented in solar resource assessment. This methodology is based on the implementation of several techniques in order to achieve a combined, fast, and robust detection system for the Sun position regardless of the conditions of the sky, which is a complex task due to the variability of the sky dynamics. Identifying the correct position of the Sun is a critical parameter to project whether, in the presence of clouds, the occlusion of the Sun is occurring, which is essential in short-term solar resource assessment, the so-called irradiance nowcasting. The experimental results confirm that the proposed methodology performs well in the detection of the position of the Sun not only in a clear-sky day, but also in a cloudy one. The proposed methodology is also a reliable tool to cover the dynamics of the sky.

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Ropelewska, Ewa, Kadir Sabanci, and Muhammet Fatih Aslan. "The Use of Digital Color Imaging and Machine Learning for the Evaluation of the Effects of Shade Drying and Open-Air Sun Drying on Mint Leaf Quality." Applied Sciences 13, no. 1 (December 23, 2022): 206. http://dx.doi.org/10.3390/app13010206.

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The objective of this study was to reveal the usefulness of image processing and machine learning for the non-destructive evaluation of the changes in mint leaves caused by two natural drying techniques. The effects of shade drying and open-air sun drying on the ventral side (upper surface) and dorsal side (lower surface) of leaves were compared. Texture parameters were extracted from the digital color images converted to color channels R, G, B, L, a, b, X, Y, and Z. Models based on image features selected for individual color channels were built for distinguishing mint leaves in terms of drying techniques and leaf side using machine learning algorithms from groups of Lazy, Rules, and Trees. In the case of classification of the images of the ventral side of fresh and shade-dried mint leaves, an average accuracy of 100% and values of Precision, Recall, F-Measure, and MCC of 1.000 were obtained for color channels B (KStar and J48 machine learning algorithms), a (KStar and J48), b (KStar), and Y (KStar). The effect of open-air sun drying was greater. Images of the ventral side of fresh and open-air sun-dried mint leaves were completely correctly distinguished (100% correctness) for more color channels and algorithms, such as color channels R and G (J48), B, a and b (KStar, JRip, and J48), and X and Y (KStar). The classification of the images of the dorsal side of fresh and shade-dried mint leaves provided 100% accuracy in the case of color channel B (KStar) and a (KStar, JRip, and J48). The fresh and open-air sun-dried mint leaves imaged on the dorsal side were correctly classified at an accuracy of 100% for selected textures from color channels a (KStar, JRip, J48), b (J48), and Z (J48). The developed approach may be used in practice to monitor the changes in the structure of mint leaves caused by drying in a non-destructive, objective, cost-effective, and fast manner without the need to damage the leaves.

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Xiao, Zhefei, Ye Zhu, Yang Hong, Tiantian Ma, and Tao Jiang. "Enhancing Sun-Dried Kelp Detection: Introducing K-YOLO, a Lightweight Model with Improved Precision and Recall." Sensors 24, no. 6 (March 20, 2024): 1971. http://dx.doi.org/10.3390/s24061971.

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Kelp, often referred to as a “sea vegetable”, holds substantial economic significance. Currently, the drying process for kelp in China primarily relies on outdoor sun-drying methods. Detecting kelp in the field presents challenges arising from issues such as overlapping and obstruction. To address these challenges, this study introduces a lightweight model, K-YOLOv5, specifically designed for the precise detection of sun-dried kelp. YOLOv5-n serves as the base model, with several enhancements implemented in this study: the addition of a detection head incorporating an upsampling layer and a convolution module to improve the recognition of small objects; the integration of an enhanced I-CBAM attention mechanism, focusing on key features to enhance the detection accuracy; the replacement of the CBS module in the neck network with GSConv to reduce the computational burden and accelerate the inference speed; and the optimization of the IoU algorithm to improve the identification of overlapping kelp. Utilizing drone-captured images of sun-dried kelp, a dataset comprising 2190 images is curated. Validation on this self-constructed dataset indicates that the improved K-YOLOv5 model significantly enhances the detection accuracy, achieving 88% precision and 78.4% recall. These values represent 6.8% and 8.6% improvements over the original model, respectively, meeting the requirements for the real-time recognition of sun-dried kelp.

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Savinykh, V. P., S. G. Gospodinov, S. A. Kudzh, V. Ya Tsvetkov, and I. P. Deshko. "Semantics of visual models in space research." Russian Technological Journal 10, no. 2 (April 3, 2022): 51–58. http://dx.doi.org/10.32362/2500-316x-2022-10-2-51-58.

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Objectives. The aim of the study is to develop a methodology for assessing the semantics of weakly structured or morphologically complex visual information models. In order to achieve the goal, a criterion for classifying visual models as complex and an algorithm for obtaining a gradient image with several levels of density were introduced. The gradient image is not binary, thus increasing the reliability of finding boundaries or contours. An auxiliary structural visual model was introduced, and a series of images of different densities was used in processing. Next, the concept of a conditional image coordinate system was introduced. This allows for information to be transferred from different visual models to a synthetic resulting visual model.Methods. Using gradient image processing and constructing a new intermediate structural model allows models with different densities to be linked. A system of conditional image coordinates was introduced and a series of models with different densities to obtain a synthetic image was processed.Results. The visual models obtained from satellite images with poor visibility of objects were processed in the Sun– Earth–Moon system. The Sun–Earth system was chosen as the basis. A characteristic of space images is the fact that the bright light of the Sun “clogs” the images of other objects with large phase angles. The use of the contouring technique allows for the visibility of images of low brightness and high brightness to be equalised. The shift of the frequency response after detection of all objects enabled the formation of a clear visual model.Conclusions. In primary visual models, low brightness images were not visible. They appeared when exposure was increased, while high-density objects merged into one. Because of this, it is fundamentally impossible to obtain a high-quality image of all objects, or the complete semantics of a visual model from a single high, medium, or lowdensity image. In order to obtain the complete semantics of the visual model, a series of images need to be processed with the transfer of images to a common synthetic image. The proposed technique allowed for such problems to be resolved. A comparison of the results obtained using the methods of processing a single image proved the reliability and high information content of the method.

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Wijitworasart, Warit, Zoe de Beurs, and Andrew Vanderburg. "A Dataset for Exploring Stellar Activity in Astrometric Measurements from SDO Images of the Sun." Research Notes of the AAS 7, no. 8 (August 7, 2023): 168. http://dx.doi.org/10.3847/2515-5172/aced3b.

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Abstract We present a data set for investigating the impact of stellar activity on astrometric measurements using NASA’s Solar Dynamics Observatory (SDO) images of the Sun. The sensitivity of astrometry for detecting exoplanets is limited by stellar activity (e.g., starspots), which causes the measured “center of flux” of the star to deviate from the true, geometric, center, producing false positive detections. We analyze Helioseismic and Magnetic Imager continuum image data obtained from SDO between 2015 July and 2022 December to examine this “astrometric jitter” phenomenon for the Sun. We employ data processing procedures to clean the images and compute the time series of the sunspot-induced shift between the center of flux and the geometric center. The resulting time series show quasiperiodic variations up to 0.05% of the Sun’s radius at its rotation period.

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Ga, Deog-Hyeon, Seung-Taek Oh, and Jae-Hyun Lim. "A DNN-Based UVI Calculation Method Using Representative Color Information of Sun Object Images." Sensors 21, no. 22 (November 22, 2021): 7766. http://dx.doi.org/10.3390/s21227766.

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As outdoor activities are necessary for maintaining our health, research interest in environmental conditions such as the weather, atmosphere, and ultraviolet (UV) radiation is increasing. In particular, UV radiation, which can benefit or harm the human body depending on the degree of exposure, is recognized as an essential environmental factor that needs to be identified. However, unlike the weather and atmospheric conditions, which can be identified to some extent by the naked eye, UV radiation corresponds to wavelength bands that humans cannot recognize; hence, the intensity of UV radiation cannot be measured. Recently, although devices and sensors that can measure UV radiation have been launched, it is very difficult for ordinary users to acquire ambient UV radiation information directly because of the cost and inconvenience caused by operating separate devices. Herein, a deep neural network (DNN)-based ultraviolet index (UVI) calculation method is proposed using representative color information of sun object images. First, Mask-region-based convolutional neural networks (R-CNN) are applied to sky images to extract sun object regions and then detect the representative color of the sun object regions. Then, a deep learning model is constructed to calculate the UVI by inputting RGB color values, which are representative colors detected later along with the altitude angle and azimuth of the sun at that time. After selecting each day of spring and autumn, the performance of the proposed method was tested, and it was confirmed that accurate UVI could be calculated within a range of mean absolute error of 0.3.

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van der Sluijs, Marinus Anthony. "The Dragon of the Eclipses—A Note." Culture and Cosmos 13, no. 1 (June 2009): 62–74. http://dx.doi.org/10.46472/cc.0113.0207.

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The astrological concept of the ‘dragon of the lunar nodes’, responsible for eclipses of the sun and the moon, may have derived from a combination of ideas prevailing in Late Antiquity with respect to the ourobóros or ‘tail-biting serpent’—that it constituted a ring of darkness, that it was bent around the sun and that it was positioned on the ecliptic band. Various Mithraic, astrological and alchemical images of celestial dragons appear to represent this aspect of the dragon.

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Sekrecka, Aleksandra, Damian Wierzbicki, and Michal Kedzierski. "Influence of the Sun Position and Platform Orientation on the Quality of Imagery Obtained from Unmanned Aerial Vehicles." Remote Sensing 12, no. 6 (March 24, 2020): 1040. http://dx.doi.org/10.3390/rs12061040.

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Images acquired at a low altitude can be the source of accurate information about various environmental phenomena. Often, however, this information is distorted by various factors, so a correction of the images needs to be performed to recreate the actual reflective properties of the imaged area. Due to the low flight altitude, the correction of images from UAVs (unmanned aerial vehicles) is usually limited to noise reduction and detector errors. The article shows the influence of the Sun position and platform deviation angles on the quality of images obtained by UAVs. Tilting the camera placed on an unmanned platform leads to incorrect exposures of imagery, and the order of this distortion depends on the position of the Sun during imaging. An image can be considered in three-dimensional space, where the x and y coordinates determine the position of the pixel and the third dimension determines its exposure. This assumption is the basis for the proposed method of image exposure compensation. A three-dimensional transformation by rotation is used to determine the adjustment matrix to correct the image quality. The adjustments depend on the angles of the platform and the difference between the direction of flight and the position of the Sun. An additional factor regulates the value of the adjustment depending on the ratio of the pitch and roll angles. The experiments were carried out for two sets of data obtained with different unmanned systems. The correction method used can improve the block exposure by up to 60%. The method gives the best results for simple systems, not equipped with lighting compensation systems.

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Xiao, Perry, and Daqing Chen. "The Effect of Sun Tan Lotion on Skin by Using Skin TEWL and Skin Water Content Measurements." Sensors 22, no. 9 (May 9, 2022): 3595. http://dx.doi.org/10.3390/s22093595.

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Stratum corneum (SC) is the outermost skin layer. SC hydration is important for its cosmetic properties and barrier function. SC trans-epidermal water loss (TEWL) measurements and skin water content measurements are two key indexes used for SC characterisation. The instrument stability and accuracy are vitally important when measuring small changes. In this paper, we present our latest study on the effect of sun tan lotion on skin by using skin TEWL and skin water content measurements. We developed techniques to improve the measurement stability and to visualise small changes, as well as developed machine learning algorithms for processing the skin capacitive images. The overall results show that TEWL and skin water content measurements are capable of measuring the subtle changes of skin conditions due to the application of sun tan lotions. The results show that the TEWL values decreased after the sun tan lotion application. The sun tan lotion with SPF 20 had the lowest decrease, whilst the sun tan lotion with SPF 50+ had the highest decrease. The results also show that the skin water content increased after the sun tan lotion application, with SPF 20 having the highest increase, whilst SPF 50+ had the lowest increase.

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Oberoi, Divya, Surajit Mondal, Rohit Sharma, Shabbir Bawaji, Ujjaini Alam, and Ayan Biswas. "Understanding Weak Impulsive Narrowband Quiet Sun Emissions (WINQSEs)." Proceedings of the International Astronomical Union 18, S372 (August 2022): 121–22. http://dx.doi.org/10.1017/s1743921322005099.

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AbstractThe confluence of data from the Murchison Widefield Array and an imaging pipeline tailored for spectroscopic snapshot images of the Sun at low radio frequencies have led to enormous improvements in the imaging quality of the Sun. These developments have lowered the detection thresholds by up to two orders of magnitude as compared to earlier studies, and have enabled the discovery of Weak Impulsive Narrowband Quiet Sun Emissions (WINQSEs). Their spatial distribution and various other properties are consistent with being the radio signatures of coronal nanoflares hypothesized by Parker (1988) to explain coronal heating in the quiet Sun emissions. We present the status of the multiple projects we have been pursuing to improve the detection and characterisation of WINQSEs, ranging from looking for them in multiple independent datasets using independent detection techniques to looking for their counter parts to estimate the energy associated with them and understanding their morphologies.

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Lee, Jennifer Dorothy. "Chasing the sun: Qu Leilei's serial images in early post-Mao China." Journal of Contemporary Chinese Art 6, no. 2 (September 1, 2019): 225–41. http://dx.doi.org/10.1386/jcca_00005_1.

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Abstract 'You always treat the sun as though it were yours.' Lining the frame of a pen-and-ink sketch, these words reflect conditions of possibility particular to the contemporaneity of early post-Mao China. Included in his Visual Diary series from the early 1980s, Qu Leilei's image-text turns inward the heavily socialized forms of visual and political expression from the revolutionary era. As instances of the artist's emerging private practice, such works, including etchings, line drawings, and fragments of prose poetry, are seldom addressed in existing scholarship on contemporary Chinese art. This article takes up a selective examination of Qu's diaristic ephemera from this historical moment following the Cultural Revolution (1966‐76) to explore how Qu's entries both maintain and transform aspects of revolutionary-era media and visuality. The article further considers the following questions: In what ways does Qu's Visual Diary reconfigure the serial images of revolutionary state-driven practices in the social landscape of still-Maoist Beijing? How do Qu's transfigured image-texts complicate the rejection of Maoist visual vanguardism in cultural practices after the revolution?

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Tollestrup, E. V., G. G. Fazio, J. Woolaway, J. Blackwell, and K. Brecher. "Infrared Images of the Sun During the July 11, 1991 Solar Eclipse." Symposium - International Astronomical Union 154 (1994): 179–83. http://dx.doi.org/10.1017/s0074180900124416.

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Infrared images (1.65 μm) of the eclipsed Sim were taken atop Mauna Kea, Hawaii, during the July 11, 1991 total eclipse with an Amber Engineering 128 × 128 InSb array camera. The camera, mounted on a portable solar tracker, had a 3.8-cm, f/2 objective that produced a 4.9° field of view. The primary objective of the experiment was to search for dust or rocky rings around the Sun, previously detected at about 4 R⊙. High thin clouds, atmospheric dust and aerosols from the June 1991 explosion of Mount Pinatubo in the Philippines, and the overall brightness of the solar corona resulted in a very high infrared background. Despite this, high signal-to-noise radial infrared intensity profiles were obtained of the solar corona from the Moon's limb out to about 10 R⊙. Preliminary analysis shows some evidence for an enhanced surface brightness between 3 to 4 R⊙ along the east-west direction, but much fainter than seen in previous solar eclipses. The transition region between the K-corona and the F-corona clearly shows at 2.5 R⊙, and the surface brightness of the F-corona as a function of radius (from about 2 to 10 R⊙) can be fit by a simple power law.

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Alonso, J., F. J. Batlles, C. Villarroel, Rosa Ayala, and J. I. Burgaleta. "Determination of the sun area in sky camera images using radiometric data." Energy Conversion and Management 78 (February 2014): 24–31. http://dx.doi.org/10.1016/j.enconman.2013.10.050.

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Duan, Puhong, Jibao Lai, Jian Kang, Xudong Kang, Pedram Ghamisi, and Shutao Li. "Texture-aware total variation-based removal of sun glint in hyperspectral images." ISPRS Journal of Photogrammetry and Remote Sensing 166 (August 2020): 359–72. http://dx.doi.org/10.1016/j.isprsjprs.2020.06.009.

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Witze, Alexandra. "Staring at the Sun — close-up images from space rewrite solar science." Nature 622, no. 7984 (October 25, 2023): 684–85. http://dx.doi.org/10.1038/d41586-023-03301-1.

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Journal articles on the topic 'Sun-images'

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