Shifting Horizons - A Line and Its Movement in Art, History and Philosophy

What happens when horizons shift? More specifically, what occurs when that line, which in everyday experience appears so consistent and omnipresent, reveals itself to be contingent? And if the horizon line is mutable, what does that imply about the systems of knowledge, order, and faith that the seemingly immutable horizon appears to neatly delimit and order? These are the questions that the volume of essays addresses, offering perspectives from multiple historical periods and disciplines that tackle instances in literature, history, and art in which shifts in conceptualizing the horizon made themselves manifest.

Horizon Line Detection in Historical Terrestrial Images in Mountainous Terrain Based on the Region Covariance

Horizon line detection is an important prerequisite for numerous tasks including the automatic estimation of the unknown camera parameters for images taken in mountainous terrain. In contrast to modern images, historical photographs contain no color information and have reduced image quality. In particular, missing color information in combination with high alpine terrain, partly covered with snow or glaciers, poses a challenge for automatic horizon detection. Therefore, a robust and accurate approach for horizon line detection in historical monochrome images in mountainous terrain was developed. For the detection of potential horizon pixels, an edge detector is learned based on the region covariance as texture descriptor. In combination with shortest path search the horizon in monochrome images is accurately detected. We evaluated our approach on 250 selected historical monochrome images in average dating back to 1950. In 85% of the images the horizon was detected with an error less than 10 pixels. In order to further evaluate the performance, an additional dataset consisting of modern color images was used. Our method, using only grayscale information, achieves comparable results with methods based on color information. In comparison with other methods using only grayscale information, accuracy of the detected horizons is significantly improved. Furthermore, the influence of color, choice of neighborhood for the shortest path calculation, and patch size for the calculation of the region covariance were investigated. The results show that both the availability of color information and increasing the patch size for the calculation of the region covariance improve the accuracy of the detected horizons.

DETERMINING THE IMPORTANCE THE INFLUENCE OF TECHNOLOGICAL FACTORS ON THE RESTORATION REINFORCED CONCRETE STRUCTURES

The article made an analytical study, by expert estimates, the determination of the importance of technological factors that have the greatest impact on the physical and mechanical properties of recovered parts of concrete structures. Technological factors were identified during the analysis of scientific literature. For the consideration of the experts was presented eight technological factors, namely: the stiffness, the repair mixture; seal; thickness of the recovery layer; the ambient temperature when performing rehabilitation works; condition of the surfaces of the concrete samples (the surface can be cleaned, stripped, with notches artificially destroyed...); the method of preparing the repair surface (use of contact layer); moisture content of the repair surface (dry, damp, wet); provision and maintenance Department relative to the horizon line (the position of the top "floor"; the side – "wall"; bottom – "ceiling"). The information obtained from experts, were edited on the basis of mathematical (statistical) method. The calculated estimate of the average degree of agreement of opinions of all experts and assessment of the significance of coefficient of concordance. Determined weight factors are considered: preparation of the repair surface; position of the repair site relative to the horizon; the state of the surfaces of the concrete samples (the repair surface is not cleaned, cleaned, with notches artificially destroyed); the stiffness of the mixture; sealing; moisture repair surface (dry, damp, wet); the ambient temperature when performing recovery operations and the thickness of the recovery layer.

Visually Induced Motion Sickness on the Horizon

Visually induced motion sickness is an unpleasant but common side-effect of many simulations and VR-applications. We investigated whether an earth-fixed reference frame provided in the simulation is able to reduce motion sickness. To do so, we created a moving starfield that did not contain any indicators of the spatial orientation of the observer. As the observer was simulated to move through the randomly oscillating starfield, a time-to-contact task had to be carried out. Two colored stars on collision course with each other had to be spotted, then they disappeared and the time of their collision had to be judged. Eye-movements, task performance, and motion sickness were recorded. This condition without visual reference to the observer's upright was supplemented with three conditions containing either an earth-fixed fixation cross, an earth-fixed horizon line, or a line that was yoked to the head. Results show that only the earth-fixed horizon was able to significantly reduce visually induced motion sickness. Thus, a mere earth-stationary anchor does not suffice, a clear indication of earth horizontal seems necessary to reap a modest benefit.

FEATURES OF HOLOGRAPHIC PERCEPTION OF VISUAL PERSPECTIVE IN ARCHITECTURE

The article is devoted to the phenomenon of holographic human perception in the analysis of the architectural environment. Includes aspects of perspective-tonal perception of visual factors of holographic scanning of the human visual system. Aimed at understanding and reproducing the features and nuances of vision, in the context of summary analysis and reproduction of the system of energy flows in the elements of visual perception. The holographic factor of perception of reality is based on the difference between the work of the right and left eye, with the peculiarity of the angular adjustment of vision to the object of observation. The horizon line or the height of the perception of volumes, as well as the position of the spaces of the architectural environment remain dominant.

Comparative Analysis Between Recurrent Convolutional and Convolutional Neural Networks for Horizon Detection

The preliminary step in the navigation of Unmanned Vehicles is to detect and identify the horizon line. One method to locate the horizon and obstacles in an image is through a supervised learning, semantic segmentation algorithm using Neural Networks. Unmanned Aerial Vehicles (UAVs) are rapidly gaining prominence in military, commercial and civilian applications. For the safe navigation of UAVs, there poses a requirement for an accurate and efficient obstacle detection and avoidance. The position of the horizon and obstacles can also be used for adjusting flight parameters and estimating altitude. It can also be used for the navigation of Unmanned Ground Vehicles (UGV), by neglecting the part of the image above the horizon to reduce the processing time. Locating the horizon and identifying the various obstacles in an image can help in minimizing collisions and high costs due to failure of UAVs and UGVs. To achieve a robust and accurate system to aid navigation of autonomous vehicles, the efficiency and accuracy of Convolutional Neural Networks (CNN) and Recurrent-CNNs (RCNN) are analysed. It is observed via experimentation that the RCNN model classifies test images with higher accuracy.