Horizontal Edges Research Articles

Spatial change in differential stress magnitudes around the source fault before intraplate earthquakes

SUMMARYHow are the sizes of the earthquakes determined? To solve this important problem, we analysed the data from a dense temporary seismic observation network installed in the aftershock area of the 2016 Mw 6.2 Central Tottori earthquake, which occurred in an intraplate region in Japan. We compared the stress field estimated from approximately 10 000 accurate focal mechanisms of aftershocks with the calculated post-earthquake stress field and found that the differential stress before the earthquake was very small near both horizontal edges. These results did not depend significantly on the modeled slip distribution and the orientation of the principal stress before the earthquake. Similar results were obtained for the 2000 Mw 6.7 Western Tottori earthquake, which also occurred in the same intraplate region in Japan. These results suggest that the fault size of large intraplate earthquakes can be determined by the region of small differential stress surrounding future earthquake faults.

Trace Concealment Histogram-Shifting-Based Reversible Data Hiding with Improved Skipping Embedding and High-Precision Edge Predictor (ChinaMFS 2022)

Reversible data hiding (RDH) is a special class of steganography, in which the cover image can be perfectly recovered upon the extraction of the secret data. However, most image-based RDH schemes focus on improving capacity–distortion performance. In this paper, we propose a novel RDH scheme which not only effectively conceals the traces left by HS but also improves capacity–distortion performance. First, high-precision edge predictor LS-ET (Least Square predictor with Edge Type) is proposed, and the predictor divides pixels into five types, i.e., weak edge, horizontal edge, vertical edge, positive diagonal edge, and negative diagonal edge. Different types of target pixels utilize different training pixels with stronger local consistency to improve accuracy. Then, a novel prediction-based histogram-shifting (HS) framework is designed to conceal embedding traces in the stego images. Finally, we improve both the data-coding method and the skipping embedding strategy to improve the image quality. Experimental results demonstrate that the capacity–distortion performance of the proposed scheme outperforms the other trace concealment schemes and is comparable to the state-of-the-art schemes utilizing sorting technique, multiple histogram modification, and excellent LS-based predictors. Moreover, it can conceal the embedding traces left by the traditional HS schemes to a certain extent, reducing the risk of being steganalyzed.

A flexible Python-based touchscreen chamber for operant conditioning reveals improved visual perception of cardinal orientations in mice.

Natural scenes are composed of a wide range of edge angles and spatial frequencies, with a strong overrepresentation of vertical and horizontal edges. Correspondingly, many mammalian species are much better at discriminating these cardinal orientations compared to obliques. A potential reason for this increased performance could be an increased number of neurons in the visual cortex that are tuned to cardinal orientations, which is likely to be an adaptation to the natural scene statistics. Such biased angular tuning has recently been shown in the mouse primary visual cortex. However, it is still unknown if mice also show a perceptual dominance of cardinal orientations. Here, we describe the design of a novel custom-built touchscreen chamber that allows testing natural scene perception and orientation discrimination performance by applying different task designs. Using this chamber, we applied an iterative convergence towards orientation discrimination thresholds for cardinal or oblique orientations in different cohorts of mice. Surprisingly, the expert discrimination performance was similar for both groups but showed large inter-individual differences in performance and training time. To study the discrimination of cardinal and oblique stimuli in the same mice, we, therefore, applied, a different training regime where mice learned to discriminate cardinal and oblique gratings in parallel. Parallel training revealed a higher task performance for cardinal orientations in an early phase of the training. The performance for both orientations became similar after prolonged training, suggesting that learning permits equally high perceptual tuning towards oblique stimuli. In summary, our custom-built touchscreen chamber offers a flexible tool to test natural visual perception in rodents and revealed a training-induced increase in the perception of oblique gratings. The touchscreen chamber is entirely open-source, easy to build, and freely available to the scientific community to conduct visual or multimodal behavioral studies. It is also based on the FAIR principles for data management and sharing and could therefore serve as a catalyst for testing the perception of complex and natural visual stimuli across behavioral labs.

Robust natural depth for anticorrelated random dot stereogram for edge stimuli, but minimal reversed depth for embedded circular stimuli, irrespective of eccentricity.

The small differences between the images formed in our left and right eyes are an important cue to the three-dimensional structure of scenes. These disparities are encoded by binocular neurons in the visual cortex. At the earliest stage of processing, these respond to binocular correlation between images. We assessed the perception of depth in anticorrelated stimuli, in which the contrast polarity in one eye is reversed, as a function of their location in the retinal image, and their depth configuration (a horizontal edge or a circle surrounded by an annulus) We found that, regardless of stimulus eccentricity, participants perceived depth in the natural direction for edge stimuli, and weakened, reversed depth for circular stimuli.

On the Structure of Singular Points of a Solution to Newton’s Least Resistance Problem

We consider the following problem stated in 1993 by Buttazzo and Kawohl (Math Intell 15:7–12, 1993): minimize the functional $${\int \limits } {\int \limits }_{\Omega } (1 + |\nabla u(x,y)|^{2})^{-1} dx dy$$ in the class of concave functions u : Ω → [0,M], where $${\Omega } \subset \mathbb {R}^{2}$$ is a convex domain and M > 0. It generalizes the classical minimization problem, which was initially stated by I. Newton in 1687 in the more restricted class of radial functions. The problem is not solved until now; there is even nothing known about the structure of singular points of a solution. In this paper we, first, solve a family of auxiliary 2D least resistance problems and, second, apply the obtained results to study singular points of a solution to our original problem. More precisely, we derive a necessary condition for a point being a ridge singular point of a solution and prove, in particular, that all ridge singular points with horizontal edge lie on the top level and zero level sets.

Single-pixel imaging for edge images using deep neural networks.

Edge images are often used in computer vision, cellular morphology, and surveillance cameras, and are sufficient to identify the type of object. Single-pixel imaging (SPI) is a promising technique for wide-wavelength, low-light-level measurements. Conventional SPI-based edge-enhanced techniques have used shifting illumination patterns; however, this increases the number of the illumination patterns. We propose two deep neural networks to obtain SPI-based edge images without shifting illumination patterns. The first network is an end-to-end mapping between the measured intensities and entire edge image. The latter comprises two path convolutional layers for restoring horizontal and vertical edges individually; subsequently, both edges are combined to obtain full edge reconstructions, such as in the Sobel filter.

Test and Simulation of Horizontal Tail Leading Edge Impacted by Bird

Test and Simulation of Horizontal Tail Leading Edge Impacted by Bird

Applications for Green Technology Practices in Analyzing the Edge Detection Techniques on Digital Image Processing by using MATLAB

Increasing awareness and growing focus on environmental issues such as climate change, energy use, and the loss of non-renewable resources have created a great need for research that provides possible solutions to these problems. Environmental science and engineering research continue to play an important role in revealing new “green” future opportunities. Digital Image Processing plays a major role in contributing to its relevant research works under these Environmental and Green Technologies. By applying tools related to Environment technology this Digital Image Processing produces numerous applications. In such cases, Edges provide an important dynamic change in digital image processing. It is a process of finding and finding edges with sharp changes made by the power of its images. This is the best way to get an accurate edge in good shape and also different edge finders will work in better different conditions. Different methods of edge detection were compared comparatively to determine which method was most suitable for obtaining edges without any noise conditions. Here, the three types of edges have horizontal, vertical and diagonal edges. In this paper, we review the different editing methods and compare different identification methods, advantages, and disadvantages. Implementation is done using MATLAB. A sudden change of discontinuity is evident in the image.

Miniaturized Multilayer Surface-Mountable 5G Filter Based on Shielded Spiral Resonator

This brief presents a miniaturized bandpass filter (BPF) based on the shielded Archimedes spiral resonators using the multilayer printed circuit board (PCB) technology. The spiral resonators are incorporated inside a substrate integrated waveguide cavity, resulting in miniaturization by introducing additional coil-to-ground capacitance, and the enhancement of electromagnetic compatibility (EMC) due to the enclosed metal cavity. Detailed theoretical derivation for the resonator is presented to prove its miniaturized effect. A miniaturized 4 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> -order BPF for 5G N78 application is developed with the proposed resonators. Compactness is further realized by the multilayer geometrical arrangement, consisting of two types of inter-stage coupling. One is the horizontal edge coupling and the other is the vertical space coupling through the spiral slot. Transmission zeros (TZs) are generated on each side of the passband by source-to-load coupling. The proposed filter is featured with an extremely small volume, low loss, together with good surface-mountable characteristic.

A compact TM03 mode penta‐polarization agile MSA for interference mitigation in 5G ultra‐dense point to point environment

Signal interference in the recent 5G ultra-dense environment is becoming severe due to the co-existence of large RF nodes operating in the constrained spectrum. In this article, a polarization agile approach for the designing of an RF system is studied to mitigate interference issues besides the communication and signal processing approach. A compact single-fed single layer penta-polarization agile higher-order microstrip patch is analyzed probably for the first time in the literature. The proposed antenna possesses a very low profile of less than 0.01 λ (λ free-space wavelength). Reconfigurable orthogonal feeding with switches is connected with the horizontal and vertical patch edges. Subsequently, these are excited separately and simultaneously using switchable PIN diodes and appropriate bias networks to realize horizontal, vertical, and 45° slant polarization states. Successively, diagonal patch corners are truncated to initiate right and left-hand circular polarizations. Slots are etched on specific orientation of currents on the patch surface to improve side-lobe levels. A prototype is analyzed, simulated, and fabricated at TM03 mode and operating at 5.8 GHz band with penta-polarization agility. A consistent 11 dBi realized broadside gain is measured covering the 10 dB reflection loss and 3 dB axial ratio bandwidth in both the principal planes.

Influence of different visual guiding facilities in urban road tunnel on driver’s spatial right-of-way perception

Urban road tunnel construction is becoming ever more prevalent, and traffic safety in tunnel operation is even more important. This study evaluates the influence of different visual guiding facilities on drivers’ spatial right-of-way perception by combining quantitative and qualitative methods in order to provide a basis for traffic safety optimization in the tunnel. Simulation scenes were designed for six common types of visual guiding facilities as comprising no facility (baseline), horizontal strips, edge markers, LED arch, vertical stripes, and combination (multiple) facilities. An eye tracker was used to obtain eye movement data of subject drivers exposed to various scenes. After each driving test, psychological feeling of the subjects in tunnel driving, and their ratings of alignment and contour guidance of various facilities were obtained by questionnaires. The research results showed that setting locations and facility types have a great impact on drivers’ glance location and glance duration. When horizontal stripes, edge markers, LED arch and vertical stripes were set separately, alignment guidance and contour guidance performance were found to vary in inverse proportion. Horizontal stripes and edge markers are the preferred and necessary facilities, which are conducive to ensuring longitudinal and horizontal rights-of-way. LED arch and vertical stripes are also good supplements to spatial right-of-way. The combination of these 4 types of facilities can provide multi-level alignment guidance and contour guidance functions, which is beneficial to traffic safety in the tunnel.

An Edge Distortion and CNN-Based Analysis of Blind IQ

This paper is for assessing the image quality (IQ) without using an authentic image (original image) which is a type of Blind IQ Assessment (BIQA) model by introducing a technique of Convolutional Neural Network (CNN). The distortions of edges in the image are considered as features to represent the image feature vector. This approach is justified by the evidence that the subjective evaluation concentrates on image characteristics that radiate from the boundaries and edges that exist with in the image. It was identified in the prior methods that the features are extracted at the time of training or before training by applying sophisticated transformations on the image. In this work, the vertical along with horizontal edge feature maps of the training images are extracted by means of Scharr Kernel (SK) approach. These edge maps subsequently fed into a CNN, which uses non-linear transformations to bring out higher-level features. Regression is then used to link the generated features to the IQ score. To accommodate different sizes of input images, the SPP (Spatial Pyramid Pooling) layer is used in this network. The developed model was evaluated using well-known datasets in the field of IQA. The suggested model's performance reveals that it outperforms previously existing models in context of negligible complexity involvement and feature extraction simplicity.

Numerical simulation and application of soft computing in estimating vertical drop energy dissipation with horizontal serrated edge

Abstract In the present study, FLOW-3D software was used to simulate energy dissipation by a serrated-edge drop, downstream of this structure. For this purpose, 2, 3, and 4 serrations with 2 series of relative dimensions at the edge of the vertical drop, with a relative critical depth range of 0.2–0.35 were used for simulation. Then, using artificial neural network (ANN), support vector machine (SVM), and gene expression program (GEP) methods, the accuracy of numerical models was evaluated. Results showed that increasing dimensions of the edges increased energy dissipation, and the highest and lowest energy dissipation was related to the models with 3 and 4 serrations, respectively, Compared to the edgeless state, the 4-edge model, with relative dimension of 0.1, increased energy dissipation by an average of 20%, and the 3-edge model, with relative dimension of 0.15, by an average of 69%. Results of energy dissipation prediction using ANN, SVM, and GEP methods showed that although all three models have good accuracy for estimating energy dissipation, the accuracy of ANN method with RMSE of 0.0081 and R2 of 0.9938 in the training phase and RMSE of 0.0125 and R2 of 0.9805 in the testing phase, is higher than the other two methods.

A novel dual-loop ground-radiation antenna for circularly polarized GNSS applications

In this investigation, a circularly polarized (CP) dual-loop ground-radiation antenna has been proposed for GPS applications using a transverse loop and a longitudinal loop. The transverse loop is designed within an 8 mm × 4.5 mm (0.042λ × 0.024λ) clearance, installed at the horizontal edge of the ground plane for excitation of the ground mode along the y-axis, whereas a 1 mm × 10 mm (0.005λ × 0.053λ) longitudinal loop is etched at the vertical edge of the ground plane for excitation of the ground mode along the x-axis. In this way, the magnitudes and phases of the orthogonal components of the radiated electric field have been controlled independently, satisfying the CP conditions. The proposed antenna produced right-hand circular polarization towards the + z-axis, which has been verified using rectangular and square-shaped ground planes. Both simulation and measurement were conducted, and the measured axial ratio bandwidth with reference to 3 dB was 20 MHz (1.27%) while the impedance bandwidth with reference to −6 dB was 141 MHz (8.95%).

The foehn effect during easterly flow over Svalbard

Abstract. This article presents a comprehensive analysis of the foehn episode which occurred over Svalbard on 30–31 May 2017. This episode is well documented by multiplatform measurements carried out during the Arctic CLoud Observations Using airborne measurements during polar Day (ACLOUD) and Physical feedbacks of Arctic PBL, Sea ice, Cloud And AerosoL (PASCAL) campaigns. Both orographic wind modification and foehn warming are considered here. The latter is found to be primarily produced by the isentropic drawdown, which is evident from observations and mesoscale numerical modeling. The structure of the observed foehn warming was in many aspects very similar to that for foehns over the Antarctic Peninsula. In particular, it is found that the warming was proportional to the height of the mountain ridges and propagated far downstream. Also, a strong spatial heterogeneity of the foehn warming was observed with a clear cold footprint associated with gap flows along the mountain valleys and fjords. On the downstream side, a shallow stably stratified boundary layer below a well-mixed layer formed over the snow-covered land and cold open water. The foehn warming downwind of Svalbard strengthened the north–south horizontal temperature gradient across the ice edge near the northern tip of Svalbard. This suggests that the associated baroclinicity might have strengthened the observed northern tip jet. A positive daytime radiative budget on the surface, increased by the foehn clearance, along with the downward sensible heat flux provoked accelerated snowmelt in the mountain valleys in Ny-Ålesund and Adventdalen, which suggests a potentially large effect of the frequently observed Svalbard foehns on the snow cover and the glacier heat and mass balance.

Effects of glaucoma on detection and discrimination of image blur.

PurposeBlur is one of the most commonly reported visual symptoms of glaucoma, but it is not directly measured by current clinical tests. We aimed to investigate the effects of glaucoma on detection and discrimination of image blur.MethodsParticipants were people with glaucoma, separated into two groups with (n = 15) or without (n = 17) central visual field defects measured by 10–2 perimetry, and an age‐similar control group (n = 18). First, we measured contrast detection thresholds centrally using a 2‐interval forced choice procedure. We then measured blur detection and discrimination thresholds for the same stimuli (reference blurs 0, 1 arcmin) using a 2‐alternative forced choice procedure under two contrast conditions: 4× individual detection threshold for the low contrast condition; 95% contrast for the high contrast condition. The stimulus was a horizontal edge bisecting a hard‐edged circle of 4.5° diameter. Data were analysed by linear mixed modelling.ResultsContrast detection thresholds for the glaucoma group with central visual field defects were raised by 0.01 ± 0.004 (mean ± SE, Michelson units) (p = 0.002) and by 0.01 ± 0.004 (p = 0.03) relative to control and glaucoma without central visual field defect groups, respectively. Blur detection and discrimination thresholds were similar between groups, with small elevations in blur detection thresholds in the glaucoma groups not reaching statistical significance (detection p = 0.29, discrimination p = 0.91). The lower contrast level increased thresholds from the higher contrast level by 1.30 ± 0.10 arcmin (p < 0.001) and 1.05 ± 0.10 arcmin (p < 0.001) for blur detection and discrimination thresholds, respectively.ConclusionsEarly‐moderate glaucoma resulted in only minimal elevations of blur detection thresholds that did not reach statistical significance in this study. Despite the prevalence of blur as a visual symptom of glaucoma, psychophysical measurements of blur detection or discrimination may not be good candidates for development as clinical tests for glaucoma.

First-principles study on controlling transport gap of graphene nanoribbons using hybrid Armchair–Zigzag nanostructures

The electronic and transport properties of hybrid armchair–zigzag nanostructures, which include right-angles-shaped GNRs, U-shaped GNRs, and patterned nanopores structured GRNs, were studied by the combination of density functional theory and nonequilibrium Green’s function method. The density of state, electron transmission spectra, and molecular orbitals were analyzed. The obtained results show that right-angles-shaped GNRs junctions tend to open a transport gap when the numbers of right-angles are greater than or equal to 4. The gap increases insignificantly as the numbers of right-angles are greater than 4. It implies that the U-shaped GNR junction, corresponding to 4 right-angles structure, is a potential structure for controlling transport gap of GRNs. The transport gap of the U-shaped GNRs decreases as the length of horizontal edge increases. In contrast, the transport gap increases as the high of vertical edge increases. In addition, the patterned nanopore had an enormous influence on the electronic and transport properties though the armchair GNRs junctions, depending on the shape and size of nanopore. This research suggests that designed tailored GNRs based on hybrid armchair–zigzag nanostructures can be used to control the transport gap of graphene. The formation of quasi-bound states at zigzag edges of the hybrid nanostructures plays a key role.

Carbon allotropes consisting of rings and cubes

Joint horizontal and vertical edges can hinge the polygonal carbon structures. Here, five carbon allotropes are proposed based on differently connected polygonal ring structures. Based on the number of rings from the basic units, the five carbon allotropes are termed 5M14, 6M16, 4-6M12, 4-6M6 and 4M-B12, respectively. The energetic, dynamical, mechanical and thermodynamic stabilities of five carbon allotropes are confirmed by energy, phonon dispersion, elastic constants, and ab initio molecular dynamics simulations. The calculated band structure and the density of states reveal that 5M14 and 4M-B12 are indirect band gap semiconductors with a band gap of 1.22 eV and 4.15 eV, respectively. While 6M16 exhibits semimetallic conductivity, 4-6M12 and 4-6M6 have metallic conductivity. These carbon allotropes may enrich the carbon family and facilitate the applications of carbon-based materials and promote the design of unique crystalline structures.

Minimum projective linearizations of trees in linear time

The Minimum Linear Arrangement problem (MLA) consists of finding a mapping π from vertices of a graph to distinct integers that minimizes ∑{u,v}∈E|π(u)−π(v)|. In that setting, vertices are often assumed to lie on a horizontal line and edges are drawn as semicircles above said line. For trees, various algorithms are available to solve the problem in polynomial time in n=|V|. There exist variants of the MLA in which the arrangements are constrained. Iordanskii, and later Hochberg and Stallmann (HS), put forward O(n)-time algorithms that solve the problem when arrangements are constrained to be planar (also known as one-page book embeddings). We also consider linear arrangements of rooted trees that are constrained to be projective (planar embeddings where the root is not covered by any edge). Gildea and Temperley (GT) sketched an algorithm for projective arrangements which they claimed runs in O(n) but did not provide any justification of its cost. In contrast, Park and Levy claimed that GT's algorithm runs in O(nlog⁡dmax) where dmax is the maximum degree but did not provide sufficient detail. Here we correct an error in HS's algorithm for the planar case, show its relationship with the projective case, and derive simple algorithms for the projective and planar cases that run without a doubt in O(n) time.

Mining relationships between transmission clusters from contact tracing data: An application for investigating COVID-19 outbreak.

ObjectiveContact tracing of reported infections could enable close contacts to be identified, tested, and quarantined for controlling further spread. This strategy has been well demonstrated in the surveillance and control of COVID-19 (coronavirus disease 2019) epidemics. This study aims to leverage contact tracing data to investigate the degree of spread and the formation of transmission cascades composing of multiple clusters.Materials and MethodsAn algorithm on mining relationships between clusters for network analysis is proposed with 3 steps: horizontal edge creation, vertical edge consolidation, and graph reduction. The constructed network was then analyzed with information diffusion metrics and exponential-family random graph modeling. With categorization of clusters by exposure setting, the metrics were compared among cascades to identify associations between exposure settings and their network positions within the cascade using Mann-Whitney U test.ResultsExperimental results illustrated that transmission cascades containing or seeded by daily activity clusters spread faster while those containing social activity clusters propagated farther. Cascades involving work or study environments consisted of more clusters, which had a higher transmission range and scale. Social activity clusters were more likely to be connected, whereas both residence and healthcare clusters did not preferentially link to clusters belonging to the same exposure setting.ConclusionsThe proposed algorithm could contribute to in-depth epidemiologic investigation of infectious disease transmission to support targeted nonpharmaceutical intervention policies for COVID-19 epidemic control.