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Machine vision assessment methodology has become increasingly appealing for manufacturing automation due to innovations in noninvasive technologies such as eddy current and ultrasonic testing, which have enhanced the circumstances for bearing defect identification. At this point, manual detection results in low lifespans and reliability. So, we present an innovative rider optimization-driven mutated convolutional neural network (RO-MCNN) technique for surface defect detection of bearings based on machine vision. To evaluate the effectiveness of the suggested approach, samples of the bearing surface with various defects were gathered. The raw data specimens are denoised using a Gaussian filter, and the defect-oriented surface patterns are then extracted using a local binary pattern (LBP) technique. Subsequently, the MCNN model is designed to identify and categorize the various sorts of defects. Experimental results obtained high accuracy (99.0%), F1-score (98.7%), recall (98.6%) and precision (98.5%), which validate the greater of RO-MCNN over existing methods, demonstrating its capability in robustly detecting and classifying bearing defects with high precision and reliability, thereby advancing the efficacy of machine vision in industrial defect assessment. The MCNN model’s performance is improved and the loss function is decreased by using the RO method. The results of the experiments showed that the suggested RO-MCNN technique outperforms current strategies in terms of bearing defect type detection and classification.

We extend our analysis of the gauging of rigid symmetries in bosonic two-dimensional sigma models with Wess–Zumino terms in the action to the case of world-sheets with defects. A structure that permits a non-anomalous coupling of such sigma models to world-sheet gauge fields of arbitrary topology is analyzed, together with obstructions to its existence, and the classification of its inequivalent choices.

We present results on the modeling of on- and off-ramps in cellular automata for traffic flow, especially the Nagel–Schreckenberg model. We study two different types of on-ramps that cause qualitatively the same effects. In a certain density regime ρ_low < ρ < ρ_high one observes plateau formation in the fundamental diagram. The plateau value depends on the input-rate of cars at the on-ramp. The on-ramp acts as a local perturbation that separates the system into two regimes: A regime of free flow and another one where only jammed states exist. This phase separation is the reason for the plateau formation and implies a behavior analogous to that of stationary defects. This analogy allows to perform very fast simulations of complex traffic networks with a large number of on- and off-ramps because one can parametrise on-ramps in an exceedingly easy way.

We define and study a few properties of a class of random automata networks. While regular finite one-dimensional cellular automata are defined on periodic lattices, these automata networks, called randomized cellular automata, are defined on random directed graphs with constant out-degrees and evolve according to cellular automaton rules. For some families of rules, a few typical a priori unexpected results are presented.

A general concept of the long-range elastic interactions in continuous medium is proposed. The interaction is determined as a consequence of symmetry breaking of the elastic field distribution produced by the topological defect as isolated inclusions. It is proposed to treat topological defects as the source of elastic field that can be described in terms of this field. The source is considered as a nonlinear object which determines the effective charge of the field at large distances in the linear theory. The models of the nonlinear source are proposed.

In this paper, we study topological defect lines in two character rational conformal field theories. Among them one set of two character theories are commutant pairs in $E_{8,1}$ conformal field theory. Using these defect lines, we construct defect partition function in the $E_8$ theory. We find that the defects preserve only a part of the $E_8$ current algebra symmetry. We also determine the defect partition function in $c=24$ CFTs using these defects lines of two character theories and we find that, with appropriate choice of commutant pairs, these defects preserve all current algebra symmetries of $c=24$ CFTs.

In this paper we describe how relativistic field theories containing defects are equivalent to a class of boundary field theories. As a consequence previously derived results for boundaries can be directly applied to defects, these results include reduction formulas, the Coleman–Thun mechanism and Cutcosky rules. For integrable theories the defect crossing unitarity equation can be derived and defect operator found. For a generic purely transmitting impurity we use the boundary bootstrap method to obtain solutions of the defect Yang–Baxter equation. The groundstate energy on the strip with defects is also calculated.

We perform canonical quantization of the WZW model with defects and permutation branes. We establish symplectomorphism between phase space of WZW model with N defects on cylinder and phase space of Chern–Simons theory on annulus times R with N Wilson lines, and between phase space of WZW model with N defects on strip and Chern–Simons theory on disk times R with N + 2 Wilson lines. We obtained also symplectomorphism between phase space of the N-fold product of the WZW model on strip with boundary conditions specified by permutation branes, and phase space of Chern–Simons theory on sphere times R with N holes and two Wilson lines.

Using the AdS/CFT correspondence, we study the anisotropic charge transport properties of both supersymmetric and nonsupersymmetric matter fields on (2+1)-dimensional defects coupled to a (3+1)-dimensional "heat bath." We focus on the cases of a finite external background magnetic field, finite net charge density and finite mass and their combinations. In this context, we also discuss the limitations due to operator mixing that appears in a few situations and that we ignore in our analysis. At high frequencies, we discover a spectrum of quasiparticle resonances due to the magnetic field and finite density and at small frequencies, we perform a Drude-like expansion around the DC limit. Both of these regimes display many generic features and some features that we attribute to strong coupling, such as a minimum DC conductivity and an unusual behavior of the "cyclotron" and plasmon frequencies, which become related to the resonances found in the conformal case in an earlier paper. We further study the hydrodynamic regime and the relaxation properties, from which the system displays a set of different possible transitions to the collisionless regime. The mass dependence can be cast in two regimes: a generic relativistic behavior dominated by the UV and a nonlinear hydrodynamic behavior dominated by the IR. In the massless case, we furthermore extend earlier results from the literature to find an interesting selfduality under a transformation of the conductivity and the exchange of density and magnetic field.

In this paper, we analyze the Cardy–Lewellen equation in general diagonal model. We show that in these models it takes a simple form due to some general properties of conformal field theories, like pentagon equations and OPE associativity. This implies that the Cardy–Lewellen equation has a simple form also in nonrational diagonal models. We specialize our finding to the Liouville and Toda field theories. In particular, we prove that recently conjectured defects in Toda field theory indeed satisfy the cluster equation. We also derive the Cardy–Lewellen equation in all sl(n) Toda field theories and prove that the form of boundary states found recently in sl(3) Toda field theory holds in all sl(n) theories as well.

The thixoformability and defect formation of AZ91D magnesium alloy are studied with different processing parameters including reheating temperature, time and die temperature. The results indicated that the suitable processing parameters should be reheating temperature between 575-595°C, reheating time more than 75 min, and die temperature over 275°C. Four types of defects, coldshut, liquid segregation, microporosity and cracks, have been observed in the thixoformed products if the processing parameters are not controlled properly. Among these defects, microporosity and cracks are always dominant.

We explain the mechanism of defect screening in GaInN/GaN quantum wells, which are used as active layers in white and blue light emitting diodes (LEDs). Despite the fact that these devices have now been commercially available for some time, the reason for the high luminescence efficiency had not been really understood. The high defect densities in these devices commonly would not allow the use as an optical emitter. We present the mechanism turning an actually poor-quality material into a powerful optical emitter.

Surface conditions of aluminum can influence the final arrangement of nano-pores in fabrication of ordered nanoporous anodic alumina membranes (AAMs). This study is mainly focused on the different applied voltages of aluminum electropolishing by keeping all the other parameters constant. After heat treatment (stress relieving and annealing at 500°C) of pure aluminum sheets, the samples were electropolished at different voltages (10-60V) to obtain desirable surface smoothness, while the temperature of the container was kept constant. The current-time curves were recorded during electropolishing process. The surface roughness obtained in each applied voltage was examined using optical microscope and atomic force microscope (AFM). The process was followed by two-step anodization in order to reach ordered nano-pores. Finally, the influence of surface roughness on regularity of nano-pores was observed using scanning electron microscope (SEM). The SEM images were analyzed to investigate the morphology and the degree of self ordering of pores of the samples by using a new designed analytical method aiming MATLAB and fast Fourier transform (FFT) technique. It was concluded that the electropolishing voltage and the resulted surface roughness and also formed defects can competitively affect the arrangement of membrane's nano-pores. A desired smoothness obtained from electropolishing voltage of 30V. Also 40V provided the best order with respect to the other voltages.

The effects of vacancies on the strength and elastic constants of silicon, such as Young's modulus and Poisson's ratio are investigated using the molecular dynamics simulations with the Stillinger–Weber potential. The defected crystalline cells contain randomly generated defect distributions in the simulation models. The ideal strength is found to be 33.6 GPa at the strain 0.26. The Young's modulus and Poisson's ratio is 148 GPa and 0.252, respectively. It is found that the strength decreases as the point defect fraction increases, and the variation of the strength versus the point defect fraction coincides with a decaying exponential function. In addition, vacancies are shown to reduce the elastic constants. In general, the elastic constants of silicon vary linearly versus the defect fraction.

We have carried out thermally stimulated current (TSC) measurements on as-grown Tl₂Ga₂S₃Se layered single crystals in the temperature range 10–60 K with different heating rates of 0.6–1.5 K s¹. The data were analyzed by curve fitting, initial rise, and peak shape methods. The results were in good agreement with each other. Experimental evidence was obtained for trapping center in Tl₂Ga₂S₃Se crystal with activation energy of 11 meV. The capture cross section and concentration of the traps were found to be 1.5 × 10^-23cm² and 1.44 × 10¹⁰cm^-3, respectively. Analysis of the TSC data at different light excitation temperatures leads to a value of 18meV/decade for the traps distribution.

Structural relaxation by isothermal annealing below the glass transition temperature is conducted on a Zr_64.13Cu_15.75Ni_10.12Al₁₀ bulk metallic glass. The effect of structural relaxation on thermal and mechanical properties was investigated by differential scanning calorimetry and instrumented nanoindentation. The recovery of the enthalpy in the DSC curves indicates that thermally unstable defects were annihilated through structural relaxation. During nanoindentation, the structural relaxation did not have a significant influence on the serrated plastic flow behavior. However, Structural relaxation shows an obvious effect in increasing both the hardness and elastic modulus, which is attributed to the annihilation of thermally unstable defects that resulted from the relaxation.

Positron annihilation lifetime spectroscopy and Doppler broadening annihilation line-shape measurements were carried out in 40 MeV alpha-irradiated undoped InSb. After irradiation the sample was subjected to an isochronal annealing over temperature region of 25°C–400°C with annealing time of 30 min at each set temperature. After each annealing the positron measurements were carried out at room temperature. Formation of radiation induced defects and their recovery with annealing temperature were investigated. A three component positron lifetime analysis was undertaken to observe the trapping of positrons in the sample after irradiation and during annealing. The average positron lifetime value τ_avg = 313 ps at room temperature after irradiation indicated the presence of defects and the high value of τ₂ at room temperature suggested that the probable defects were divacancies. A two stage recovery of defects was observed during post irradiation isochronal annealing over the temperature region 25°C–400°C. The variations in line-shape parameter (S) and defect specific parameter (R) during annealing in the temperature region 25°C–400°C resembled the behavior of τ_avg indicating the migration of vacancies, formation of vacancy clusters and the disappearance of defects between 300°C to 400°C.

A molecular dynamics (MD) based computational intelligence (CI) approach is proposed to investigate the Young modulus of two graphene sheets: Armchair and Zigzag. In this approach, the effect of aspect ratio, the temperature, the number of atomic planes and the vacancy defects on the Young modulus of two graphene sheets are first analyzed using the MD simulation. The data obtained using the MD simulation is then fed into the paradigm of a CI cluster comprising of genetic programming, which was specifically designed to formulate the explicit relationship of Young modulus of two graphene structures. We find that the MD-based-CI model is able to model the Young modulus of two graphene structures very well, which compiles in good agreement with that of experimental results obtained from the literature. Additionally, we also conducted sensitivity and parametric analysis and found that the number of defects has the most dominating influence on the Young modulus of two graphene structures.

Target waves in excitable media such as neuronal network can regulate the spatial distribution and orderliness as a continuous pacemaker. Three different schemes are used to develop stable target wave in the network, and the potential mechanism for emergence of target waves in the excitable media is investigated. For example, a local pacing driven by external periodical forcing can generate stable target wave in the excitable media, furthermore, heterogeneity and local feedback under self-feedback coupling are also effective to generate continuous target wave as well. To discern the difference of these target waves, a statistical synchronization factor is defined by using mean field theory and artificial defects are introduced into the network to block the target wave, thus the robustness of these target waves could be detected. However, these target waves developed from the above mentioned schemes show different robustness to the blocking from artificial defects. A regular network of Hindmarsh–Rose neurons is designed in a two-dimensional square array, target waves are induced by using three different ways, and then some artificial defects, which are associated with anatomical defects, are set in the network to detect the effect of defects blocking on the travelling waves. It confirms that the robustness of target waves to defects blocking depends on the intrinsic properties (ways to generate target wave) of target waves.

The effect of H₂ forming gas annealing on the microwave properties of $\mathrm{\text{Ba}}({\mathrm{\text{Zn}}}_{1/3}{\mathrm{\text{Ta}}}_{2/3}){\mathrm{\text{O}}}_3$ (BZT) dielectric ceramics has been studied. The structural, microwave, DC electrical and optical properties were analyzed by experiment results. With elevated temperature annealing, the microwave loss of BZT was increased. This trend correlated with high DC conductivity of annealed samples, as well as dampened phonons found in Raman spectra. These evidences, together, prove that the enhancement of oxygen vacancy defects induced by oxygen deficient sintering environment is one of the main extrinsic root causes for the high microwave loss in practical ceramic materials.