sGrapp: Butterfly Approximation in Streaming Graphs

We study the fundamental problem of butterfly (i.e., (2,2)-bicliques) counting in bipartite streaming graphs. Similar to triangles in unipartite graphs, enumerating butterflies is crucial in understanding the structure of bipartite graphs. This benefits many applications where studying the cohesion in a graph shaped data is of particular interest. Examples include investigating the structure of computational graphs or input graphs to the algorithms, as well as dynamic phenomena and analytic tasks over complex real graphs. Butterfly counting is computationally expensive, and known techniques do not scale to large graphs; the problem is even harder in streaming graphs. In this article, following a data-driven methodology, we first conduct an empirical analysis to uncover temporal organizing principles of butterflies in real streaming graphs and then we introduce an approximate adaptive window-based algorithm, sGrapp, for counting butterflies as well as its optimized version sGrapp-x. sGrapp is designed to operate efficiently and effectively over any graph stream with any temporal behavior. Experimental studies of sGrapp and sGrapp-x show superior performance in terms of both accuracy and efficiency.

Construct in Assessments of Spoken Language

Language assessment constructs conjoin two complex, dynamic phenomena: collective patterns of language use and individual language ability. Assessment constructs emerge from “spheres of activity” across multiple, overlapping dimensions, denoted in this chapter as theoretical, operationalized, stated, and perceived constructs. While theoretical constructs are assumptions about what causes differences in scores, the operationalized construct is what actually emerges in the interaction between the assessee and the assessment infrastructure. Stated constructs are descriptions of what the assessment claims to assess, and perceived constructs are the ways these statements are interpreted. Interrogating the congruence of these dimensions has the potential to provide a holistic view of the development, experience, use, and impact of assessment constructs across diverse stakeholder worlds.

Editorial of Special Issue “Detecting Geospace Perturbations Caused by Earth”

A systematic multiparametric and multiplatform approach to detect and study geo-space perturbations attributed to preparation processes related to natural hazards is fundamental in order to obtain useful insights on a series of complex dynamic phenomena of the Earth system, namely, earthquakes, volcanic and Saharan dust events, as well as geomagnetic disturbances [...]

CentrifugationSynchronization Control of Fractional Order Chaotic Systems Based on Memristor and Its Hardware Implementation

This paper studies the synchronization control of fractional order chaotic systems based on memristor and its hardware implementation. This paper takes the complex dynamic phenomena of memristor turbidity system as the research background. Starting with the integer order memristor system, the fractional order form is derived based on the integer order turbid system, and its dynamics is deeply studied. At the same time, the turbidity phenomenon is applied to the watermark encryption algorithm, which effectively improves the confidentiality of the algorithm. Finally, in order to suppress the occurrence of turbidity, a fractional order sliding mode controller is proposed. In this paper, the sliding mode controller under the function switching control method is established, and the conditions for the parameters of the sliding mode controller are derived. Finally, the experimental results analyze the stability of the controlled system under different parameters, and give the corresponding time-domain waveform to verify the correctness of the theoretical analysis.

Structural analysis of the comet 45P/Honda based on isophote modeling

The work focuses on using the isophote method to construct a 45P/Honda comet model. At the same time, important problems were solved for modeling the physical surface of a comet and studying the structure of the cometary nucleus. This is due to the fact that, on the basis of modern studies of meteoroids, complex internal processes and dynamic phenomena on their surface have been discovered. The study of comet nuclei is of great importance, since, according to the theory of their formation, they were formed from the matter of the protoplanetary disk. Thus, modeling and analysis of the structure of various comets make it possible to create a more accurate theory of their evolution. This made it possible to evaluate the structural parameters more accurately and reliably. This allowed for the evaluation of the structural parameters more accurately and reliably. Isophotes of the nucleus, coma and tail of comet 45P/Honda were determined. Depending on the point where the comet is located on the trajectory of its orbit, one can see structural changes in the comet’s brightness from the nucleus to the peripheral region. Near the cometary nucleus, the isophotes are circular in shape. If in the center of the model the isophotes have a shape close to narrow rings, then elongations in the direction of the cometary tail and thickening of their structure appear towards the peripheral regions. Large and small tail rays can be distinguished, and the nucleus is well marked. In the future, the author’s method for modeling isophotes, developed in this work, will allow studying the structure of various cometary objects, and, based on the results, determine the degree of comet activity. On the other hand, about the development of the theory of dynamic processes and the evolution of the Solar system, one can use the data on changes in cometary activity in the process of its movement around the Sun.

A Decentralized Fuzzy Rule-Based Approach for Computing Topological Relations between Spatial Dynamic Continuous Phenomena with Vague Boundaries Using Sensor Data

Sensor networks (SN) are increasingly used for the observation and monitoring of spatiotemporal phenomena and their dynamics such as pollution, noise and forest fires. In multisensory systems, a sensor node may be equipped with different sensing units to observe and detect several spatiotemporal phenomena at the same time. Simultaneous detection of different phenomena can be used to infer their spatial interactions over space and time. For this purpose, decentralized spatial computing approaches have shown their potential for effective reasoning on spatial phenomena within a sensor network. However, in most cases, spatial extents of continuous dynamic phenomena are uncertain, and their relations and interactions cannot be inferred by the existing approaches at the sensor node level. To address this limitation, in this paper, we propose and develop a decentralized fuzzy rule-based spatial reasoning approach to depict the spatial relations that hold between two evolving spatial phenomena with fuzzy boundaries. The proposed method benefits from a more adapted fuzzy-crisp representation of dynamic phenomena observed by SN where each vague phenomenon is composed of five distinguished zones including the kernel, conjecture and exterior zone and their boundaries. For each detected phenomenon, a sensor node will report one of these zones based on its location. Aggregation of the information reported from the sensor nodes allows reasoning on spatial relations between the observed phenomena and their evolution. Such spatial information provides users with more valuable near real-time information on the state of different phenomena that can be used for informed decision-making.

Improving the Performance of Steel Machining Processes through Cutting by Vibration Control

Machining processes through cutting are accompanied by dynamic phenomena that influence the quality of the processed surfaces. Thus, this research aimed to design, make, and use a tool with optimal functional geometry, which allowed a reduction of the dynamic phenomena that occur in the cutting process. In order to carry out the research, the process of cutting by front turning with transversal advance was taken into account. Additionally, semi-finished products with a diameter of Ø = 150 mm made of C45 steel were chosen for processing (1.0503). The manufacturing processes were performed with the help of two tools: a cutting tool, the classic construction version, and another that was the improved construction version. In the first stage of the research, an analysis was made of the vibrations that appear in the cutting process when using the two types of tools. Vibration analysis considered the following: use of the Fast Fourier Transform (FFT) method, application of the Short-Time Fourier-Transformation (STFT) method, and observation of the acceleration of vibrations recorded during processing. After the vibration analysis, the roughness of the surfaces was measured and the parameter Ra was taken into account, but a series of diagrams were also drawn regarding the curved profiles, filtered profiles, and Abbott–Firestone curve. The research showed that use of the tool that is the improved constructive variant allows accentuated reduction of vibrations correlated with an improvement of the quality of the processed surfaces.

REGULARITIES OF CHANGES IN THE GAS-DYNAMIC AND GEOMECHANICAL SITUATION AT POTASH MINES

Mining operations in potash and salt deposits are complicated by gas emissions and gas dynamic phenomena. The analysis of a large number of gas dynamic phenomena and intense gas emissions at potash mines in Russia and Belarus allowed the authors to identify some patterns. In particular, it was found that the maximum number of gas dynamic phenomena occurs in the 7–10 year of operation of the mines. The purpose of the study is to analyze and identify available information on the influence of heliophysical and manmade factors on the state of rock massifs, which will allow purposefully predicting and preventing the manifestations of these factors, increasing labor safety and efficiency of mining enterprises. Research methods: methods of a full-scale mine experiment to determine the gas content of rocks and the gas content of workings, as well as analysis of statistical data. The results of the study showed that the analysis of data on 84 cases of gas dynamic phenomena at the mines of PJSC Uralkali revealed an increase in the volume of gas emissions from the developed lavas spaces at the mines of JSC Belaruskali as a result of a drop in barometric pressure on the surface. In conclusion, it can be noted that the combination of natural factors together with a powerful man-made impact on the environment creates certain prerequisites for disasters of various scales, ranging from destructive earthquakes to subsidence of mountain pressure, gas dynamic phenomena and intense gas emissions in mines and mines. The set of established patterns formed the basis for the development of a number of preventive measures that increase the safe working conditions of miners and the efficiency of mining enterprises.