Please, Help Me! I Am Lost in Zoom

LostInZoom is a new research project that will seek to design novel ways of zooming into multi-scale maps, to overcome the desert fog effect that occurs with current multi-scale cartography techniques. The desert fog effect makes you feel lost for a few seconds after a zoom in or out, because the map has changed. The idea developed in this project is to propose anchor-based zooming techniques, where salient landmarks salient at multiple scales serve as anchors between maps during the zoom. This paper discusses the main challenges that will be addressed in this project: (1) better understand and measure the desert fog effect with maps; (2) defining and modelling the best anchors for anchor-based zooming; (3) designing more progressive multi-scale maps to host these anchors; (4) designing staged animations based on anchors between maps at different scales.

Perbaikan Visibilitas pada Citra Berkabut Kawah Gunung Berapi Kelud Menggunakan Color Attenuation Prior

Mount Kelud is one of the volcanoes that erupted in 2014. To observe the activity, CCTV has been installed in the crater peak of Mount Kelud. The crater of Mount Kelud emits gases coming from the bottom of the crater. The gas makes CCTV surveillance undisturbed so that the resulting image will have noise. By using dehazing, visibility can be improved so that the resulting image can be seen clearly. The method used for this operation is Color Attenuation Prior. In the early stages, there is a dark channel process that works to turn low-intensity pixels dark. The second step is to estimate the atmospheric light from the dark channel image. This process is almost in parallel with the estimation of the depth map. The fourth step is estimating the transmission map, which functions to transmit low-intensity pixels to high-intensity pixels. The last one is the radiance recovery scene. The results show that the foggy image is successful, and it eliminates the fog effect, thus enhancing the visibility of the image. And from questionnaire results, we got 80 % positive results from all respondents. Further research so that it can be applied directly or in real-time.

Fractional-Order Anisotropic Diffusion for Defogging of RGB Images

This paper proposes a novel and efficient algorithm for defogging of color (RGB) images. The fog in a scene is mostly due to the attenuation and airlight map, which decrease the quality of the image of the scene. To enhance such images from the visual point of view, a fractional-order anisotropic diffusion algorithm with [Formula: see text]-Laplace norm is proposed for removing the fog effect. In particular, a coupling term is added in order to model the inter-channel correlations. The weights used in the coupling term stop the transmission of diffusion with in the edges, thus balances the inter-channel data in the diffusion procedure. Experimental results validate the better performance of the proposed algorithm over some of the existing anisotropic diffusion-based methods. The proposed method is independent of the measure of fog in the images, thus images with different amount of fog can be enhanced.

Radiative transfer distortions of Lyman α emitters: a new Fingers-of-God damping in the clustering in redshift space

ABSTRACT Complex radiative transfer (RT) of the Lyman α photons poses a theoretical challenge to galaxy surveys that infer the large-scale structure with Lyman α emitters (LAEs). Guided by RT simulations, prior studies investigated the impact of RT on the large-scale LAE clustering, and claimed that RT induces a selection effect which results in an anisotropic distortion even in real space but in an otherwise negligible effect in redshift space. However, our previous study, which relies on a full RT code run on the Illustris simulations, shows that the anisotropic selection effect was drastically reduced with higher spatial resolution. Adopting the same simulation framework, we further study the impact of RT on the LAE clustering in redshift space. Since we measure LAE’s radial position through a spectral peak of Lyman α emission, the frequency shift due to RT contaminates the redshift measurement and hence the inferred radial position in redshift space. We demonstrate that this additional RT offset suppresses the LAE clustering along the line of sight, which can be interpreted as a novel Fingers-of-God (FoG) effect. To assess the FoG effect, we develop a theoretical framework modelling the impact of the RT similar to that of the small-scale peculiar velocity which is commonly studied in the context of the redshift space distortion (RSD). Although our findings strongly encourage a more careful RSD modelling in LAE surveys, we also seek a method to mitigate the additional FoG effect due to RT by making use of other information in a Lyman α spectrum.

Redshift-space distortions of the H i 21-cm intensity mapping signal due to the internal motions within galaxies

ABSTRACTThe H i 21-cm intensity mapping signal experiences redshift-space distortions due to the motion of the galaxies which contain the H i as well as the motions of the H i gas within the galaxies. A detailed modelling is essential if this signal is to be used for precision cosmology. Considering dark-matter-only simulations where the H i is assumed to reside in galaxies which are associated with haloes, in this work we introduce a technique to incorporate the H i motions within the galaxies. This is achieved through a line profile which accounts for both the rotational and random (thermal and turbulent) motions of the H i within galaxies. The functional form of the double-horned line profiles used here is motivated by observations of z = 0 spiral galaxies. Analyzing the simulated 21-cm power spectrum over the redshift range 1 ≤ z ≤ 6 we find that the H i motions within galaxies make a significant contribution that is manifested as an enhancement in the Finger of God (FoG) effect which can be modelled reasonably well through a Lorentzian damping profile with a single free parameter σp. The value of σp is significantly enhanced if motions within the galaxies are included. This is particularly important at z > 3 where σp is dominated by the internal motions and a measurement of the FoG effect here could provide a handle on the line profiles of high-redshift galaxies.

Defined wetting properties of optical surfaces

Optical surfaces equipped with specific functional properties have attracted increasing importance over the last decades. In the light of cost reduction, hydrophobic self-cleaning behavior is aspired. On the other side, hydrophilic properties are interesting due to their anti-fog effect. It has become well known that such wetting states are significantly affected by the surface morphology. For optical surfaces, however, this fact poses a problem, as surface roughness can induce light scattering. The generation of optical surfaces with specific wetting properties, hence, requires a profound understanding of the relation between the wetting and the structural surface properties. Thus, our work concentrates on a reliable acquisition of roughness data over a wide spatial frequency range as well as on the comprehensive description of the wetting states, which is needed for the establishment of such correlations. We will present our advanced wetting analysis for nanorough optical surfaces, extended by a vibration-based procedure, which is mainly for understanding and tailoring the wetting behavior of various solid-liquid systems in research and industry. Utilizing the relationships between surface roughness and wetting, it will be demonstrated how different wetting states for hydrophobicity and hydrophilicity can be realized on optical surfaces with minimized scatter losses.