638 research outputs found

    Filmy Cloud Removal on Satellite Imagery with Multispectral Conditional Generative Adversarial Nets

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    In this paper, we propose a method for cloud removal from visible light RGB satellite images by extending the conditional Generative Adversarial Networks (cGANs) from RGB images to multispectral images. Satellite images have been widely utilized for various purposes, such as natural environment monitoring (pollution, forest or rivers), transportation improvement and prompt emergency response to disasters. However, the obscurity caused by clouds makes it unstable to monitor the situation on the ground with the visible light camera. Images captured by a longer wavelength are introduced to reduce the effects of clouds. Synthetic Aperture Radar (SAR) is such an example that improves visibility even the clouds exist. On the other hand, the spatial resolution decreases as the wavelength increases. Furthermore, the images captured by long wavelengths differs considerably from those captured by visible light in terms of their appearance. Therefore, we propose a network that can remove clouds and generate visible light images from the multispectral images taken as inputs. This is achieved by extending the input channels of cGANs to be compatible with multispectral images. The networks are trained to output images that are close to the ground truth using the images synthesized with clouds over the ground truth as inputs. In the available dataset, the proportion of images of the forest or the sea is very high, which will introduce bias in the training dataset if uniformly sampled from the original dataset. Thus, we utilize the t-Distributed Stochastic Neighbor Embedding (t-SNE) to improve the problem of bias in the training dataset. Finally, we confirm the feasibility of the proposed network on the dataset of four bands images, which include three visible light bands and one near-infrared (NIR) band

    Yamato-86789: A heated CM-like carbonaceous chondrite

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    We have studied the mineralogy and petrology of the Yamato (Y)-86789 meteorite and concluded that this meteorite is a new member of heated carbonaceous chondrites with CI-CM affinities. Y-86789 contains 14vol% of translucent chondrules which mainly consist of fibrous phyllosilicate-like materials. The high abundance of the phyllosilicate-like minerals in chondrules suggests severe aqueous alteration. Major parts of the matrix are also composed of the phyllosilicate-like materials. The phyllosilicate-like materials have compositions of a mixture of serpentine and saponite. However, the phyllosilicate-like materials show consistently high analytical totals; thus, they are dehydrated. X-ray diffraction measurements of the phyllosilicate-like materials reveal that they are mainly composed of olivine. Diffractions from serpentine and saponite are absent from the X-ray powder patterns. These results suggest that Y-86789 has experienced heating and the phyllosilicate minerals which were once present in Y-86789 were dehydrated to from anhydrous materials such as olivine. Y-86789 has textural, mineralogical, and compositional characteristics similar to those of Y-86720,which is one of the three unusual Antarctic carbonaceous chondrites with CI-CM affinities that show evidence of dehydration. Chondrules are completely replaced by the phyllosilicate-like materials and are surrounded by fine-grained rims. Some chondrules contain Ca-carbonates. There is an abundance of troilite in the matrix, but magnetite and PCP, which are common in CM chondrites, are absent. Some large troilite grains have a euhedral lath-like morphology. The bulk chemical composition of Y-86789 is also similar to that of Y-86720. On the basis of these similarities, we propose that Y-86789 and Y-86720 are paired meteorites

    Trace element concentrations in iron type cosmic spherules determined by the SR-XRF method

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    The X-ray fluorescence method using synchrotron radiation (SR-XRF) was applied to determine trace element abundances in iron type (I-type) cosmic spherules collected at deep-sea sediments. Cr, Co, and Ni were detected from almost all spherules and average concentrations are 1336,2991ppm, and 4.0%, respectively. Ga, Ge, and Mn were detected from 20,30,and 20% of spherules and average concentrations are 4,4 and 486ppm, respectively. Spherules containing metallic cores were enriched in Ni and Co and depleted in volatile elements such as Ga and Ge relative to those without cores. The Ni and Co enrichments resulted from high concentrations of the elements in the metallic cores, while the Ga and Ge depletion might indicate that core-bearing spherules have experienced more severe heating during atmospheric entry than the core-lacking ones. On the basis of Mn concentration we divided spherules into two groups : high and low Mn groups. Trace element abundances of the low Mn group are systematically fractionated relative to those of iron meteorites : volatile elements are depleted and refractory ones are enriched in the spherules. This appears to be consistent with the hypothesis that I-type spherules are ablation products of iron meteorites that have lost volatile elements during melting. Production of the low Mn spherules by ablation of chondritic meteorites is also possible, but chondrite melting should have occurred under a limited range of oxygen fugacity in order to enrich Cr and remove Mn in the spherules. Spherules belonging to high Mn group show a complex trace element pattern when normalized to chondrites. A large Mn excess relative to Cr in this type of spherules can not be explained by any formation process, thus it is difficult to infer the precursor material of the Mn-rich spherules

    Leukemia autopsies in Japan

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    For the purpose to know whether the annual increase of leukemia incidence in Japan is due to some leukemogenic factors or due to the increased detection rate, the authors made some statistical survey of autopsy cases in which the diagnosis is reliable and not any type of leukemias escape the detection. The results showed that acute leukemias, which are found mostly in younger age, is actually increasing. In addition, it has been deduced that among the suspected factors the increase in ionizing radiation will be one of the most probable factors for the increase in leukemia incidence</p

    Kinetic Simulations of Neoclassical and Anomalous Transport Processes in Helical Systems

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    Drift kinetic and gyrokinetic theories and simulations are powerful means for quantitative predictions of neoclassical and anomalous transport fluxes in helical systems such as the Large Helical Device (LHD). The δf Monte Carlo particle simulation code, FORTEC-3D, is used to predict radial profiles of the neoclassical particle and heat transport fluxes and the radial electric field in helical systems. The radial electric field profiles in the LHD plasmas are calculated from the ambipolarity condition for the neoclassical particle fluxes obtained by the global simulations using the FORTEC-3D code, in which effects of ion or electron finite orbit widths are included. Gyrokinetic Vlasov simulations using the GKV code verify the theoretical prediction that the neoclassical optimization of helical magnetic configuration enhances the zonal flow generation which leads to the reduction of the turbulent heat diffusivity χi due to the ion temperature gradient (ITG) turbulence. Comparisons between results for the high ion temperature LHD experiment and the gyrokinetic simulations using the GKV-X code show that the χi profile and the poloidal wave number spectrum of the density fluctuation obtained from the simulations are in reasonable agreements with the experimental results. It is predicted theoretically and confirmed by the linear GKV simulations that the E × B rotation due to the background radial electric field Er can enhance the zonal-flow response to a given source. Thus, in helical systems, the turbulent transport is linked to the neoclassical transport through Er which is determined from the ambipolar condition for neoclassical particle fluxes and influences the zonal flow generation leading to reduction of the turbulent transport. In order to investigate the Er effect on the regulation of the turbulent transport by the zonal flow generation, the flux-tube bundle model is proposed as a new method for multiscale gyrokinetic simulations
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