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With the powerful learning ability of deep convolutional networks, deep clustering methods can extract the most discriminative information from individual data and produce more satisfactory clustering results. However, existing deep clustering methods usually ignore the relationship between the data. Fortunately, the graph convolutional network can handle such relationship, opening up a new research direction for deep clustering. In this paper, we propose a cross-attention based deep clustering framework, named Cross-Attention Fusion based Enhanced Graph Convolutional Network (CaEGCN), which contains four main modules: the cross-attention fusion module which innovatively concatenates the Content Auto-encoder module (CAE) relating to the individual data and Graph Convolutional Auto-encoder module (GAE) relating to the relationship between the data in a layer-by-layer manner, and the self-supervised model that highlights the discriminative information for clustering tasks. While the cross-attention fusion module fuses two kinds of heterogeneous representation, the CAE module supplements the content information for the GAE module, which avoids the over-smoothing problem of GCN. In the GAE module, two novel loss functions are proposed that reconstruct the content and relationship between the data, respectively. Finally, the self-supervised module constrains the distributions of the middle layer representations of CAE and GAE to be consistent. Experimental results on different types of datasets prove the superiority and robustness of the proposed CaEGCN.

The concept of “middle layer” (ML) is one of the most frequent terms in current education policy. Yet, the literature on the topic is fragmented and the concept itself is defined in several different ways which hinders effective discussion. The main goals of the article are as follows: 1) to imbed current discussion in the scholar literature and provide basic overview of scholar literature; 2) clarify the terminology and delimit various meanings of the “middle layer” concept. The article is structured as follows. First, the methodology of literature review is described. Then the basic meaning of ML in various educational systems is explained. In the next part of the paper, the literature review on ML is provided. In so doing, two strands of literature are distinguished. While the research-oriented strand focuses on analysis of what ML does (and does not), the practical stream relates to what ML should (or should not) do. Based on previous analysis, the paper argues that four meanings of middle layer can be delimited. These meanings are shortly labelled as follows: (a) a loose network of local actors; (b) a coordinated and interacting system of actors; (c) an organized set of several core local organizations; (d) a regional public administration institution. These four definitions are defined and explained. The article concludes with several implications for educational policy in the Czech Republic.

As autonomous vehicle development continues at growing speeds, so does the need to optimize, diagnose, and test various elements of autonomous systems under different conditions. Since such processes should be carried out in parallel, it may result in bottlenecks in development and increased complexity. The trend for Digital Twins offers a promising option for the diagnosis and testing to be carried out separately from the physical devices, incl. autonomous vehicles in the virtual world. The idea of intercommunication between virtual and physical twins provides possibilities to estimate risks, drawbacks, physical damages to the vehicleâs drive systems, and the physical vehicleʼs critical conditions. Although providing communications between these systems arises at the speed that will be adequate to represent the physical vehicle in the virtual world correctly, it is still a trendy topic. This paper aims to demonstrate the enhancement of communications by using the Robot Operating System (ROS) as a middleware interface between two twinning systems by the example of the autonomous vehicleʼs propulsion drive. Data gathered from the physical and virtual worlds can be exchanged in the middle to allow for continuous training and optimization of the propulsion drive model, which would lead to more efficient path planning and energy-efficient drive of the autonomous vehicle itself. Additionally, a comparative analysis of ROS and its next version ROS2 is provided, discussing their differences and outlining drawbacks.

Rutting is the most common distress of the asphalt pavement with a semirigid base, mainly when located on a steep longitudinal slope. Previous studies have shown that shear stress is the leading cause of rutting. Therefore, it is essential to analyze the distribution characteristics of shear stress to evaluate pavement rutting performance. Firstly, the truck speed was measured at different locations on the steep longitudinal slope section. Then, the calculation method of shear stress was improved based on the method of “systematic clustering.” The distribution characteristics of shear stress were studied under the different gradients, slope lengths, horizontal forces, and interlayer bond conditions. Finally, the rutting prediction model was used to evaluate the rutting performance of the steep longitudinal slope section. The results show two critical parameters of a steep longitudinal slope: gradient and slope length can be quantified by establishing the relationship between truck speed and those parameters. The improved shear stress calculation method can correspond well with the layer where maximum rutting occurs. Gradients and slope lengths have little effect on shear stresses, while horizontal forces and interlayer bond conditions significantly change the shear stress distribution characteristics within the pavement. For the steep longitudinal slope sections, the rutting prediction model should consider the truck speed separately. With increasing gradient and slope length, the rutting increases the fastest in the middle layer. For sections with horizontal forces and poor interlayer bonding, the layers with the highest rutting accumulation are the upper layer and the lower layer, respectively.

In this paper, a unified method is developed to analyze free vibrations of the three-layer functionally graded cylindrical shell with non-uniform thickness. The middle layer is composed of two-dimensional functionally gradient materials (2D-FGMs), whose thickness is set as a function of smooth continuity. Four sets of artificial springs are assigned at the ends of the shells to satisfy the arbitrary boundary conditions. The Sanders’ shell theory is used to obtain the strain and curvature-displacement relations. Furthermore, the Chebyshev polynomials are selected as the admissible function to improve computational efficiency, and the equation of motion is derived by the Rayleigh–Ritz method. The effects of spring stiffness, volume fraction indexes, configuration on of shell, and the change in thickness of the middle layer on the modal characteristics of the new structural shell are also analyzed.

In this study the wear properties of chromium deposit were improved by using the nickel electrodeposited middle layers. The nickel middle layers were formed by direct current (DC) and pulse current (PC) power supplies. The results showed that the surface morphology of a chromium layer in Ni/Cr coating (DC deposited) and Ni (duty cycle = 30%, frequency = 20 Hz, PC deposited) were compact, with small nodules. Also in these coatings the crack networks density of the chromium layer decreased when compared other coatings. The hardness step value profiles with the highest value of the chromium layer and the lowest value of the nickel middle layer occurred in the studied five samples. The compact surface morphology and the appropriate hardness step value profiles of the layers were two main reasons for improving the wear resistance of the chromium layer coated on the top of the nickel layers produced by DC and PC (duty cycle = 30% and frequency = 20 Hz) currents.

Given its importance in satisfying consumers, apparel comfort is a challenge for the textile industry. If water vapor cannot escape through the garment, there will be a build-up of moisture on the ...

Key message Anther development and dehiscence is considered from an evolutionary perspective to identify drivers for differentiation, functional conservation and to identify key questions for future male reproduction research. Abstract Development of viable pollen and its timely release from the anther are essential for fertilisation of angiosperm flowers. The formation and subsequent dehiscence of the anther are under tight regulatory control, and these processes are remarkably conserved throughout the diverse families of the angiosperm clade. Anther development is a complex process, which requires timely formation and communication between the multiple somatic anther cell layers (the epidermis, endothecium, middle layer and tapetum) and the developing pollen. These layers go through regulated development and selective degeneration to facilitate the formation and ultimate release of the pollen grains. Insight into the evolution and divergence of anther development and dehiscence, especially between monocots and dicots, is driving greater understanding of the male reproductive process and increased, resilient crop yields. This review focuses on anther structure from an evolutionary perspective by highlighting their diversity across plant species. We summarise new findings that illustrate the complexities of anther development and evaluate how they challenge established models of anther form and function, and how they may help to deliver future sustainable crop yields.

The present paper deals with the description of a new species of petrified capsular fruit. The fruit is dicotyledonous, capsular formed from pentacarpellary, syncarpous ovary with parietal placentation. The fruit measures 0.12 mm in length and 0.11mm in width. It is circular, pentalocular with two fertile locules having single seed in each locules and three sterile locules. The three sterile locules contain circular parenchymatous cells which act as reserve food materials or provide buoyancy for floating mechanism. The fruit wall or pericarp measures about 4.46-5.42 µm in width and is differentiated into epicarp, mesocarp and endocarp. Outer layer epicarp is multilayered having hexagonal sclerenchymatous cell and measures about 1.10 µm in thickness. Middle layer mesocarp is multilayered having hexagonal sclerenchymatous cell and measures about 1.23 µm in thickness and inner layer endocarp is measures about 2.13 µm in thickness. The fruit is baccate type, different from any existing living family or recorded fossil fruit from the Deccan Intertrappean beds. Therefore, it is named as Baccatocarpon patanii sp. nov. The generic name is being after the baccate nature of the fruit and the specific name indicates the locality from where it was collected.

Vertical heavy metal profiling reflects the history of the deposition of metals and helps to understand the characteristics of accumulation in various layers of the sediment. Nevertheless, no previous studies in Bangladesh had focused on the vertical distribution of heavy metals in core sediments. In this study, vertical distribution, contamination level and potential ecological risks of six heavy metals (Zn, Cu, Pb, Cr, Ni, Mn) from the core sediment of ship breaking were assessed and compared with the non-ship breaking area of Bangladesh. The concentration (µg/g) of heavy metals in the 0–10 cm (surface), 10–20 cm (middle) and 20–30 cm (bottom) of sediment cores was as follows, respectively: Zn (35.54–100.68, 37.27–258.02, 42.78–66.45); Cu (16.38–75.25, 30.64–92.02, 34.99–52.98); Pb (4.84–132.08, BDL–204.48, BDL–23.51); Cr (14.57–42.13, 25.31–42.71, 15.26–36.34); Ni (4.02–42.23, 4.94–43.70, 4.40–43.13); Mn (198.74–764.16, 257.77–980.50, 255.62–856.44). The heavy metal content of core sediment from the shipbreaking region was substantially higher than that of non-shipbreaking area. Except for Ni, heavy metal content was highest in the middle layer, followed by the upper and lower layers of the sediment core. Contamination exponents such as enrichment factor, contamination factor and geo-accumulation index (Igeo) revealed contamination by Zn, Cu and Pb while potential ecological risk factor ( $$E_{r}^{i}$$ ) and risk index suggested low ecological risk by studied heavy metals except for Pb. Correlation matrix, cluster analysis and principal component analysis indicated that all studied heavy metals could have similar anthropogenic origins.

Using the computer-based simulation method within the scope of continuous mechanics, impact interaction with a speed of 3000 m/s between a steel ball and a transparent armor target is calculated (the target has three layers). The face layer of the transparent armor is made of aluminum oxynitride; the middle layer, of hardened glass; and the lower layer, of polycarbonate. The influence of the angle of the projectile approach to the target and thickness of the hardened glass layer on the process of target penetration is studied.

In this study, 10 different types of walls were made by fiber reinforced self-compacting concrete. The concrete walls were reinforced with steel and nylon fibers. The results of rheological tests showed that the steel and nylon fibers have a negative effect on flowability of self-compacting concrete, which the negative effect of steel fibers was more significant in this regard. On the other hand, the results of mechanical tests indicated that the steel fibers have a slight effect on the compressive strength and considerable effect on tensile and flexural strength, whereas, nylon fibers have no significant effect in these cases. In this study, two methods, including uniform distribution and targeted distribution of fibers, were used to reinforce the concrete walls. In the uniform distribution method, all the used fibers were uniformly distributed in the wall, while in the targeted distribution method the used fibers were distributed in the wall, with a more volume of fibers in the surrounding layers and a fewer volume of fibers in the middle layer of the wall. The concrete walls were tested by bullet fire. The results of this test showed that steel fibers could significantly decrease the penetration depth of bullet in concrete walls, while nylon fibers had a much lower effect. By comparing the penetration depth of the bullet in the walls, it was observed that the targeted distribution of fibers was effective to decrease the penetration depth of the bullet.

The surface of pollen grains is reinforced by pollen wall components produced non-cell autonomously by tapetum cells that surround developing pollen within the male floral organ, the anther. Here we show that tapetum activity is regulated by the GASSHO (GSO) receptor-like kinase pathway, controlled by two sulfated peptides, CASPARIAN STRIP INTEGRITY FACTOR 3 (CIF3) and CIF4, the precursors of which are expressed in the tapetum itself. Coordination of tapetum activity with pollen grain development depends on the action of subtilases, including AtSBT5.4, which are produced stage-specifically by developing pollen grains. Tapetum-derived CIF precursors are processed by subtilases, triggering GSO-dependent tapetum activation. We show that the GSO receptors act from the middle layer, a tissue surrounding the tapetum and developing pollen. Three concentrically organized cell types therefore cooperate to coordinate pollen wall deposition through a multilateral molecular dialog.Significance StatementPollen viability depends on a tough external barrier called the pollen wall. Pollen wall components are produced by tapetum cells which surround developing pollen grains within the anther. Precise coordination of tapetum activity with pollen grain development is required to ensure effective pollen wall formation. Here we reveal that this is achieved through a multidirectional dialogue involving three distinct cell types. We show that peptide precursors from the tapetum are activated by proteases produced stage-specifically in developing pollen grains. Unexpectedly, we found that activated peptides are perceived not in the tapetum, but in the middle layer, which encloses the developing tapetum and pollen grains, revealing an unsuspected role for this enigmatic cell layer in the control of tapetum development.