A NOVEL PERMEABILITY MODEL IN DAMAGED TREE-LIKE BIFURCATING NETWORKS CONSIDERING THE INFLUENCE OF ROUGHNESS

The seepage in tree-like bifurcating networks is a very common phenomenon in nature. The research on the transport characteristics of tree-like bifurcating networks has always been a hot topic. In this paper, a novel permeability model for fluid flow in damaged tree-like bifurcating networks is proposed. In the proposed model, the influence of roughness on permeability is considered by means of the fractal method. It is found that the permeability is not only related to the structural parameters of the network but also related to the damaged position and the number of damaged tubes at the damaged position. The effects of these parameters and damaged structure on permeability are discussed separately. The results show that the permeability reduces along with an increase in the roughness level, the length ratio, the number of damaged tubes, and the number of total bifurcating levels. Another major finding is that the permeability increases with an increase in the diameter ratio. Besides, we found that the damaged position and the number of damaged tubes at the damaged position have an important effect on the permeability. Increasing the number of damaged tubes and bringing the damaged position close to the front end of the network will reduce the permeability. Compared with the undamaged network, the permeability of damaged network has a significant decline. The proposed model may provide potential applications for the analysis of fluid flow in damaged tree-like bifurcating network.

Wavelet Analysis-Based Texture Analysis of Ceramic Surface Images

This paper is conducted to explore a new characterization method as a supplement to the traditional roughness characterization. The main research includes the extraction and evaluation of damage features of ceramic surface morphology by applying wavelet methods, the extraction of damage features in surface contours by using wavelet analysis, and the quantitative evaluation of damage degree by using damage rate and damage mean spacing. By comparing various fractal dimension calculation methods, a fractal dimension method suitable for calculating the ceramic surface was selected, and the fractal method was used to describe the ceramic surface topography as a whole. By comparing different methods of calculating the fractal dimension and further verifying them with the measured three-dimensional morphology, it is found that the vibrational method is more suitable for calculating the fractal dimension of ceramic surface, and its calculation accuracy is investigated, and the results show that the method is a reliable one. Based on the fractal theory, a mathematical model of surface wear and surface sealing was established. Further study of the model shows that the surface with a large fractal dimension has a good sealing effect; the surface corresponding to the best fractal dimension is the most resistant to wear. The fractal method can characterize the complexity of the surface profile as a whole. The wavelet method can describe the ceramic surface profile from a local perspective, and the combination of the two methods can characterize the ceramic surface well. Finally, the experimental device of the ceramic surface defect detection system is constructed, and the joint debugging of hardware and software is completed. Under different light source intensities, ceramic image samples are collected, and the accuracy detection experiments of sample defective edges are conducted, and the results show that the light source has a small impact on the accuracy of ceramic defective edge detection. The results show that the light source has more influence on the accuracy of scratch detection. The results show that the system constructed in this thesis has good applicability for different ceramic sample detection.

Choice of the Fractal Method For Visualization of Input Data While Designing Support Systems for Decision-Making by Navigator

Introduction. The constant increase in the amount and intensity of traffic requires organization and precise management.Problem Statement. In the present-day conditions, when the number of vessels engaged on internal and external routes has been growing, without the vessel driver/navigator all alone are not physically able to assess the navigation situation and to make the right decision how to operate his vessel. The need to develop and to implement algorithms that help address the issue of navigation safety is an important task, especially when it comes to the management of groups of vessels. The main approaches that allow generalizing the information flows to ensure continuous and safe navigation are the formation of a structured system of processing and evaluation of input factors and related output parameters. This enables controlling the ergatic system of vessel, given a significant number of factors.Purpose. The purpose of this research is to create new approaches to controlling the vessel ergatic system for making an optimal and timely decision.Materials and Methods. Fractal methods for representation of the primary information and applied computer programs of mathematical simulation have been used.Results. The proposed model of information processing as part of the vessel ergatic system is designed to comp­rehensively ensure the safety of vessels, while providing control and optimization of both operational and organizational parameters and diagnostic functions, with the ability to predict and to prevent failures of the vessel engineering system.Conclusions. The applicability of general algorithms for the processing of information and its structuring according to the degree of impact has been shown. The application of these approaches solves the problem of overloading the navigator with excessive navigational information and reduces decision-making time. The developedalgorithm allows creating an automatic control system for groups of vessels in real conditions of difficult navigation environment.

Shi-nematic afterimages: semiocapitalism and Chinese cine-cities

In this essay, we revisit our interdisciplinary approach to the “becoming-cinema” of Chinese life and cities in the contemporary era, while critically revisiting our notion of “shi-nema” (which combines the Chinese concept of “shi” (势) with a detoured notion of “cinematicity”) which we forward as a provocative “image for thought” that explodes the concerns of modern film studies. Revisiting our multi-scalar fractal method, on this outing we specifically engage with a nexus of new semiocapitalist images and urban sites/sights that foreground how rapidly the psychogeographic circumstances in post-socialist Chinese cine-cities evolve and mutate. Our essay opens with a fresh film-philosophy conceptualisation of “afterimages”, blending cinematic, city and conceptual varieties before moving on to critically engage with a new constellation of interviews and images drawn from Chinese film, television, streaming platforms, social media and commercial real estate apps.

Design of Minkowski Array Microstrip Fractal Antenna at 3.5 GHz Frequency for 5G Communication System

Technological developments in the field of telecommunications are experiencing rapid progress, especially the presence of 5G technology as a fifth generation cellular communication system that has many advantages at the World Radiocommunication Conference (WRC) in 2015, 5G candidate frequency bands below 6 GHz have been widely discussed, and the range the following frequencies have been suggested: 470–694, 1427–1518, 3300–3800, and 4500–4990 MHz. One of recommendation of resonant frequency is 3.5 GHz, as it is acceptable in most countries. Therefore, a reliable communication network is needed, especially in the 3.5 GHz frequency band for fifth generation applications. Antena is one of the important communication components in radio communication system. Mikrostrip Antena is a type of Antena that is currently growing because it has the advantage of having a light weight and low profile. This paper proposed development of mikrostrip Antena using the fractal method, increase the gain using the Array method, and achieve the target return loss ≤ -10 dB, VSWR ≤ 2, and gain ≥ 5 dB at frequency of 3.5 GHz for 5G communication sytsem. Proposed Antena is designed using a duroid R5880 substrate with a dielectric constant value of 2.2, a dielectric loss (tan loss) of 0.0009 and a substrate thickness (h) of 1.57 mm. This study resulted in a reduction in Antena dimensions until 53.76% with return loss of -42.48 dB, VSWR 1.02, and a gain of 8.46 dB. The results obtained in this design meet the specifications of the predetermined targets.

Using Multi-Fractal and Joint Multi-Fractal Theories to Characterise the Spatial Variability of Soil Particle Size Distribution in an Underground Coalmine Area

Underground coal mining leads to serious surface deformation, which negatively affects the physical properties of soils Soil particle size distribution (PSD) is one of the most basic soil physical characteristic that influences other important properties such as soil hydraulics and thermodynamics. Understanding the spatial variability of the soil PSD in subsided land can provide targeted guidance for land reclamation. In this study, we conducted a quantitative study on the spatial variability of the soil PSD in the Pingshuo mining area on the Loess plateau, Shanxi Province in China, and explored the effects of subsidence and reclamation on the soil PSD. A plot experiment, including one unmined plot (UMP), one subsided plot (SUP), and one reclaimed plot (RCP), was performed in Anjialing No.3 underground coal mine in the, Pingshuo mining area. Four multi-fractal parameters of the soil PSD—D(0), D(1), Δα(q), and Δf(α)—were analyzed at the three sample sites. The joint multi-fractal method was carried out to analyze the spatial correlation of the soil PSD to further reveal the impacts of coal mining subsidence and land reclamation on the soil PSD. The multi-fractal method can reflect the local non-uniformity and heterogeneity of the soil PSD, while the joint multi-fractal approach can illustrate the correlation of the soil PSD between different soil depths. The range and spatial variability of the soil PSD increased due to coal mining subsidence and the impact of subsidence on the spatial disturbance of the surface soil PSD was greater than that of the deeper layers. The spatial correlation of clay in subsided land was larger than those of unmined land and reclaimed land, whereas, for silt and sand, the correlation was smaller. Land reclamation decreased the spatial variability of the soil PSD, which was near that of the unmined land after reclamation.

A Novel Multiband Fractal Antenna for Wireless Application

This paper proposes a novel multiband antenna using circle and triangle fractals for wireless application. By cutting a triangle slot in the circular monopole, a novel fractal method of the circular nested triangle structure is presented. The above structure is iterated four times, which forms the proposed fractal antenna. The antenna adopts the microstrip feeding method. In order to improve out band rejection and expand bandwidth, a ring resonator is designed on the back of the dielectric plate. The designed antenna covers 1.8 GHz–2.9 GHz applied to Bluetooth, TD-SCDMA, WCDMA, CDMA2000, and LTE33-41, 3.4 GHz–4.6 GHz applied to LTE 42/43 and WiMAX, and 5 GHz–5.6 GHz applied to WLAN. The substrate is FR4 with a dielectric constant of 4.4 and a loss tangent of 0.02. The size of the fabricated antenna is 87.5 × 61 × 1.6 mm. The measured pick gain achieves 2.98 dBi, 2.58 dBi, and 3.34 dBi at 2.6 GHz, 3.8 GHz, and 5.3 GHz, respectively. The measurement and simulation results are in good agreement, which verifies the rationality of the design.