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Antimagic labeling of n-uniform cactus chain graphs
A graph G = (V,E) is considered antimagic if it admits antimagic labeling. The antimagic labeling of a finite, simple graph with |V | = n and |E| = m is a bijective function from the set of edges to the set of integers {1, 2,,m} such that the vertex sum of n vertices is pairwise distinct. The vertex sum of a vertex is obtained by summing the labels of all edges incident to it. Hartsfield and Ringel conjectured that every connected graph different from K2 is antimagic. Supporting this conjecture, it was shown that the dense graphs are antimagic. A cactus graph is a connected graph where no edge lies within more than one cycle. A cactus graph in which each block is a cycle of the same size n is called an n-uniform cactus graph. We proved that Hartsfield and Ringels conjecture is true for n-uniform cactus chain graphs with and without pendant vertices, which are specific cases of sparse graphs. 2026 World Scientific Publishing Company. -
Bounds on Sombor index of graph operations
Operations in graph theory have a significant influence in the theoretical and application aspect of the domain. Topological indices serve as a crucial component in chemical graph theory linked with some molecular structure. Recently, Gutman initiated the study on the Sombor index. In this paper, the computation of some bounds for Sombor index of graph operation notably join, cartesian product, corona product, lexicographic product, tensor product and strong product is carried out. The computation has been utilized to determine the upper bounds of the index for the specified graph operations for some standard graphs like the path and cycle graphs. 2025 World Scientific Publishing Company. -
Centrality measures-based sensitivity analysis and entropy of nonzero component graphs
The nonzero component graph of a finite-dimensional vector space over a finite field is a graph whose vertices are the nonzero vectors in the vector space, and any two vertices are adjacent if the corresponding linear combination contains a common basis vector. In this paper, we discuss the centrality measures and entropy of the nonzero component graph and also analyze the sensitivity of the graph using the centrality measures. 2025 World Scientific Publishing Company. -
Edge incident 2-edge coloring of graphs
The edge incident 2-edge coloring of a graph G is an edge coloring of the graph G such that not more than two colors are assigned to the edges incident to an edge e = uv in G. In other words, for every edge e in G, the edge e and all the edges that are incident to the edge e is in at most two different color classes. The edge incident 2-edge coloring number ?'ein2 (G) is the maximum number of colors in any edge incident 2-edge coloring of G. The main objective of this paper is to study the edge incident 2-edge coloring concept and apply the same to some graph classes. Besides finding the exact values of these parameters, we also obtain some bounds. 2025 World Scientific Publishing Company. -
Chromatic bounds of some (P5, banner)-free graphs
Let ?(G) and ?(G), respectively, denote the chromatic number and clique number of a graph G. A P5 is a path on five vertices, a banner (paw) is the graph obtained by joining a new vertex to a single vertex of C4 (C3) and a hammer is obtained by subdividing the pendant edge of a paw exactly once. Recently, (P5,banner)-free graphs have received wide attention. In 2019, Karthick, Maffray and Pastor, gave a structural characterisation of (P5,banner)-free graphs, which when combined with a result by Bourneuf and Thomass[Bounded twin-width graphs are polynomially ?-bounded, Adv. Comb. (2025)] implies that for a (P5,banner)-free graph G, ?(G) ? ?(G)5. Geir [Colourings of P5-Free Graphs, PhD Thesis, Technische Universit at Bergakademie Freiberg (2022)] showed that the ?-binding function of the class of (P5,banner)-free graphs is bounded by the ?-binding function of 3K1-free graphs. By a result of Kim [The Ramsey number R(3,t) has order of magnitude t2/log t, Random Structures and Algorithms 7(3) (1995) 173207], the chromatic number ?(G) of a 3K1-free graph G has order of magnitude ?(?(G)2/log ?(G)). Recently, Song and Xu [Divisibility and coloring of some P5-free graphs, Discrete Appl. Math. 348 (2024) 144151] proved that every (P5, C5, banner, hammer)-free graph G is ?(G)3/2-colorable. This motivates us to study the subclasses of (P5, banner)-free graphs. We prove that for any (P5, banner, F ? K1)-free graph G where F ?{C4,K4 ? e,K3 ? K1,paw}, ?(G) ? ?(G)2/2 for ?(G) ? 3. Moreover, the bound is tight for ?(G) = 3. 2026 World Scientific Publishing Company. -
A study on the invariant intersection graph of a graph
Analyzing the structure of the automorphism groups of graphs, and investigating the properties of graphs that are constructed from algebraic structures are two important research topics in algebraic graph theory. Blending these two aspects of study, an algebraic intersection graph, called the invariant intersection graph of a graph, has been introduced in the literature. In this paper, we study certain properties of the invariant intersection graphs of graphs, and obtain some structural characterizations of these graphs, based on the automorphism group of the graph on which the invariant intersection graph is constructed. 2026 World Scientific Publishing Company. -
Cyclic property of iterative eccentrication of trees
A tree graph is an acyclic graph. The eccentric graph of a graph G, denoted by Ge is a derived graph with the vertex set same as that of G and two vertices in Ge are adjacent if one of them is an eccentric vertex of the other. The process of finding eccentric graph of a graph is called eccentrication and that of constructing iterative eccentric graphs, denoted by Gek, is called iterative eccentrication. A graph G is said to be ?-cyclic(t,l) if G, Ge, Ge2,?, Gek, Gek+1,?, Gek+l are the only non-isomorphic graphs, and the graph Gek+l+1 is isomorphic to Gek. In this paper, we prove the existence of an ?-cycle for any tree graph on n vertices. We also obtain some important results on eccentric graphs of trees. Then, we present a conjecture on the cyclic property of eccentrication of a general graph G. Finally, an analogy between the concept of ?-cycle for a graph and the dichotomy of the Riemann sphere into Fatou sets and Julia sets is presented. We also state some open problems in the area. 2025 World Scientific Publishing Company. -
Certain variants of domatic partitions of n-inordinate invariant intersection graphs
A class of algebraic intersection graphs, called the n-inordinate invariant intersection graphs, are introduced in the literature and several properties of these graphs are being investigated. Domination in graphs is an important structural property and partitioning the vertex set of a graph into dominating sets is called the domatic partition of a graph. In this paper, we analyze the structure of the n-inordinate invariant intersection graphs by investigating certain variants of domatic partitions of these graphs, that are defined based on different types of domination in graphs. 2026 World Scientific Publishing Company. -
Some new results on anti-adjacency spectra of regular graphs
The anti-adjacency matrix A*(G) of a simple graph G with V (G) = {v1,v2,v3,vn}, is a square matrix of order n with rows and columns indexed by V (G), where the (i,j)-entry (i?j) is 1, if the vertices vi and vj are not adjacent to each other and 0, otherwise. The (i,i)- entry of A*(G) is 1. The anti-adjacency eigenvalues of G are the eigenvalues obtained from the matrix A*(G) and the corresponding spectra is called the anti-adjacency spectra of G, denoted by a-spec(G). In this paper, we discuss the anti-adjacency spectra of join and disjoint union of regular graphs. The anti-adjacency spectra of bipartite regular graphs, line graphs of regular graphs and strongly regular graphs are also discussed. 2026 World Scientific Publishing Company. -
The total upper domatic number of a graph
Let G = (V,E) be a graph with no isolated vertices. For two disjoint subsets A and B of V, if every vertex in B is adjacent to at least one vertex in A, then the set A is said to dominate set B. A partition ? = {V1,V2,,Vk} of the vertex set V is a total upper domatic partition of G if Vi dominates Vj or Vj dominates Vi or both, for any Vi,Vj ? ? and G[Vi], 1 ? i ? k, has no isolated vertices. The total upper domatic number Dt(G) of G is the maximum order of a total upper domatic partition of G. In this paper, we initiate a study on the concept of total upper domatic number and determine the bounds of Dt(G) and exact values of the same for some classes of graphs. 2025 World Scientific Publishing Company. -
Propagation of SH Waves in Piezo-Flexoelectric-Layered Structures with Imperfect Interfaces: Analytical Formulation and Data-Driven Surrogates
This study presents an analytical and data-driven investigation of shear-horizontal (SH) wave propagation in layered piezo-flexoelectric (PFE) materials with imperfect interfaces. The novelty lies in integrating flexoelectric coupling and interfacial defects within a unified dispersion framework, supported by physics-consistent machine-learning surrogates for efficient parametric analysis. Governing electromechanical equations are formulated and solved under mechanical, electrical, and interfacial continuity conditions to derive dispersion relations linking phase velocity with wavenumber, flexoelectric parameters, and interface stiffness under electrically open and short-circuited boundary conditions. The results show that flexoelectric effects strongly influence dispersion at short wavelengths, while interface imperfections significantly reduce phase velocity and increase attenuation sensitivity. Electrically open conditions enhance electromechanical coupling, whereas short-circuit conditions suppress dispersion sensitivity. To accelerate large-scale evaluations, surrogate models are developed that accurately reproduce analytical dispersion behavior with substantially reduced computational cost. The proposed hybrid framework provides improved insight into guided wave mechanics in stratified smart materials and offers an efficient tool for the analysis and design of piezo-flexoelectric structures in sensing and MEMS applications. World Scientific Publishing Europe Ltd. -
Cosmic bounce in boundary-corrected symmetric teleparallel gravity
This study delves into modified f(Q,B) gravity, with a primary emphasis on solving field equations within the FLRW metric framework. It investigates bouncing scenarios by scrutinizing two nonlinear cosmological models and assesses energy conditions to authenticate bouncing cosmologies as viable alternatives to the conventional Big Bang theory. Furthermore, this analysis extends to examining geometrical parameters to shed light on the accelerating universe, providing significant insights into the implications of modified gravity for our comprehension of cosmic evolution. In addition, a perturbative analysis is performed for both models, showing that a nearly scale-invariant scalar spectral index ns and a suppressed tensor-to-scalar ratio r can be achieved for suitable parameter ranges, thus supporting the observational viability of the proposed bouncing framework. 2025 World Scientific Publishing Company. -
Impact of Carbon Nanofiber Fillers on Surface Finish and Dimensional Accuracy in FDM-printed Polymer Composites Parts
This paper examines the effect of carbon nanofiber (CNF) reinforcement on the surface finish and dimensional accuracy of the polylactic acid (PLA) composite produced using fused deposition modeling (FDM). Twin-screw compounding was used to prepare PLA-CNF composite filaments with 03wt.% CNF with extrusion of filaments (L/D ratio 30:1, 120rpm). To prepare rectangular specimens (10 10 20mm), the filaments were printed with the nozzle size of 0.4 mm, the layer thickness of 0.1 mm, the infill density of 100%, and the print speed of 5 mm/s. Dimensional accuracy was assessed by a digital vernier caliper with a resolution of 0.01 mm, and surface roughness (Ra) was measured by a digital surface tester that was stylus-based. Every measurement was averaged three times, and the statistical examination of percent deviation and variance analysis of compositions was done. Findings show that CNF addition was important with respect to the dimensional stability and surface finish. The volume variation of the print decreased to 0.20% of PLA/3 wt.% CNF compared to 0.30% of neat PLA, which is a 33% smaller variation of the dimensional accuracy. The surface roughness also reduced as 0.70 ?m of neat PLA was reduced to 0.42 ?m of PLA/3 wt.% CNF, which is a 40% decrease. It was statistically tested that trends of consistent improvement were observed between compositions. The findings indicate that CNF reinforcement results in a higher level of geometric accuracy and less surface morphology in FDM-printed polymer composites. 2026 World Scientific Publishing Company. -
Predicting Consumers' Usage Intention Towards User-Generated Content: A Hybrid SEM-ANN Approach
With the change in the communication pattern, end-users are engaging in creating content and referring to the content created by other users while making purchase decisions. This research aims at modelling factors affecting consumers' usage intention (UI) towards user-generated content (UGC) using Need for Cognition (NfC) as a moderator of the proposed relationships. The factors affecting consumers' UI involve perceived usefulness (PU), source credibility (SC), information quality (IQ) and NfC. Further, a novel attempt has been made by using the neural network approach to assess the predictive accuracy of the model. A structured questionnaire was used to collect data from 298 consumers through a survey. Data were analysed using two-stage structural equation modelling (SEM) and artificial neural network (ANN). All the independent variables viz., PU, SC, IQ and NfC significantly affect attitude towards UGC, which in turn affects UI. Results of multi-group analysis and a series of chi-square difference tests reveal that a NfC significantly moderates the relationship between PU and attitude, as well as that between SC and attitude. The root mean square error values from the neural network analysis suggest that the models show good predictive accuracy. This study provides a novel assessment of the usage of a hybrid SEM-ANN approach for understanding of UGC by incorporating NfC as a moderator in shaping consumers' attitudes and intentions to use UGC. 2025 World Scientific Publishing Co. -
Consumer Decision Recognition Based on EEG Signals for Neuromarketing Applications
Neuromarketing is a blooming interdisciplinary field that tries to understand the biology of consumer behavior by combining neuroscience with marketing. This technique can be used to grasp consumers hidden choices, intentions and decisions by analyzing their physiological and brain signals. Electroencephalography (EEG) is one of the popular neuroimaging techniques to capture and record the neural activity of the brain. Numerous research projections have been made in this field to achieve better results. Earlier approaches did not prioritize effective EEG signal preprocessing and classification methods. This paper presents a model to recognize consumer preferences by analyzing and classifying EEG signals. In this model, EEG signals are decomposed into many subbands using wavelet transform. An enhanced wavelet thresholding method is proposed to eliminate noise from subbands. Several wavelet features are computed from each subband and then fed as input to classifiers. Finally, three different machine learning classifiers are used to classify the signal between like and dislike. The classifiers are K-Nearest Neighbor (KNN), Multilayer Perceptron (MLP) and Support Vector Machine (SVM). EEG signals from 25 people are collected to verify the developed systems performance. The effectiveness of the developed method with different classifiers is validated by varying brain lobe features and band features. In comparison to other classifiers like KNN and MLP, the designed system with the SVM classifier performs better and achieves an accuracy of 98.21%. The experimental findings for the developed system suggest that research in this area has the potential to alter and enhance marketing tactics for the benefit of both manufacturers and consumers, ultimately leading to a mutually beneficial outcome. World Scientific Publishing Company. -
On the Wave Propagation and Dynamic Response of a Spherical Cavity in Piezoelectric Microstructures via Rabotnov Kernel-Based MooreGibsonThompson Thermoelasticity Theory
This study investigates the transient dynamic response and thermomechanical stability of a transversely isotropic piezoelectric medium featuring a spherical cavity. To accurately model the small-scale effects inherent in advanced structural components, a spatiotemporal nonlocal elasticity framework of the KleinGordon type is employed, incorporating both internal length and intrinsic time scale parameters. The governing equations of the MooreGibsonThompson (MGT) thermoelastic model are reformulated using a nonsingular Rabotnov-type fractional exponential kernel, providing a robust mathematical formulation to capture memory-dependent interactions without the paradox of infinite propagation speeds. The structural boundary of the cavity is subjected to a ramp-type thermal loading and electrical grounding, simulating realistic operational conditions for sensors and actuators. Using the Laplace transform technique and the Zakian numerical inversion method, the transient distributions of temperature, displacement, stress, and electric potential are derived. The results highlight the significant influence of the Rabotnov fractional parameter and spatiotemporal nonlocality on the structural stability and wave-front characteristics. This research provides a unique medium for understanding the latest developments in fractional-order dynamics for piezoelectric micro- and nano-structures, offering practical insights for civil, aerospace, and mechanical engineering applications. 2026 World Scientific Publishing Company. -
ELECTRIC EROSION MACHINING BEHAVIOR OF TITANIUM DIOXIDE PARTICLES REINFORCED WITH AL ALLOY COMPOSITE USING TOPSIS APPROACH
This research work describes the optimization of parameters in electric discharge machining (EDM) of AlFeSi (AA8011) alloy composite using the technique for order preference by similarity to ideal solution (TOPSIS) method. Initially, the AA8011 matrix alloy was synthesized with the addition of 10 wt.% TiO2 particles through the stir casting route. Scanning electron microscopy (SEM) was used to examine the morphology of the synthesized composite, which revealed that the TiO2 particles were evenly disseminated within the alloy. The machining factors, such as peak current (Ip), pulse-on time (Ton and pulse-o time (Toff), were chosen as input, whereas the material removal rate (MRR), the surface roughness (SR), and the tool wear rate (TWR) were selected as the output responses. According to the L9 (33array, the machining experiments were conducted using a brass (Br) electrode. By employing the TOPSIS method, the optimum combination of variables was determined. Based on the analysis, the Ip of 10 amps, Ton of 200 s, and Toff of 30 s provide the highest MRR (0.2379 g/min) with lower SR (3.284 m), and TWR (0.0258 g/min). ANOVA ndings exhibited that Ton was found to be the primary noteworthy factor contributing 50.67%, next by Toff (32.98%) and Ip (13.12%), respectively. Finally, the conrmation trials were carried out using the optimal parameters, which veried the predicted results. 2026 World Scientific Publishing Company. -
Advancing Building Damage Classification Accuracy through Machine Learning-Based Model Design using High Resolution Remote Sensing Images
The ability to evaluate the damage to buildings both accurately and precisely is essential for disaster recovery, planning, and rescue services. This paper proposes a new approach based on integrating machine learning algorithms in building damage classification. To achieve higher precision in classifying the level of building damage, this research proposes a new technique that employs machine learning strategies. The researchers were able to train the model to be able to differentiate the different levels of building damage and the feature extraction was performed through machine learning. The model effectively extracts and learns multiple complex signals which represent different degrees of damage from a well picked database which include several degrees of damage. In a single pass, the Siamese U-Net can perform feature extraction and similarity measurement between two different images. The efficiency and effectiveness of the Siamese U-net model can be increased by reducing inference time, thus increasing its ability to deliver faster predictions while also improving its accuracy. The suggested Enhanced U-Net (EU-Net) could greatly increase the accuracy of building-level classification. As it turned out, the results are very promising and reach beyond traditional approaches with bringing more sample opportunities of machine learning integration in the building damage assessment context. Additionally, this study believes that the accuracy of building damage classification can be further enhanced demonstrating the usefulness of machine learning in disaster management. 2025 World Scientific Publishing Company. -
Universality of black hole thermodynamics beyond the thermal approximation
Mathur and Mehta were awarded the third prize in the 2023 Gravity Research Foundation Essay Competition for their work demonstrating the universality of black hole (BH) thermodynamics. Their research established that any Extremely Compact Object (ECO) exhibits the same thermodynamic properties as a BH, irrespective of the presence of an event horizon. This significant finding was derived under the assumption that the BH emission spectrum behaves thermally. However, compelling arguments rooted in energy conservation and the BH back reaction indicate that the spectrum of Hawking radiation cannot be perfectly thermal. In this paper, we explore the extension of Mathur and Mehtas findings to scenarios where the radiation spectrum deviates from exact thermal behavior, utilizing the concept of the BH dynamical state. 2025 World Scientific Publishing Company. -
Controlling Chaos in an Axisymmetric RayleighBard Convection in a Cylindrical Enclosure with Variable Gravity Fields
The effect of variable gravity fields that vary through the height of a viscous fluid layer in an axisymmetric convection occupying a cylindrical enclosure heated from below is investigated for various radius-to-height ratios. Linear and nonlinear analyses are performed, which makes the present work the first of its kind. A minimal Fourier-series expansion leads to a boundary eigenvalue problem with variable coefficients. Using the Maclaurin-series approach, the recurrence relations for six cases of gravity fields, namely, positively linear, negatively linear, parabolic, cubic, bi-squared, and exponential gravity fields, are generated. The eigenvalue of the problem is located using the NewtonRaphson method with an error tolerance of 10?8 for idealistic and realistic boundary conditions. The scaled-Lorenz model obtained in this paper has newly defined nondimensional parameters that capture the influence of gravity fields and pave the way to examining the dynamical system. The control of chaos for this setup is implemented using various indicators. It is found that the effect of increasing the strength of gravity is to delay the appearance of chaos for all cases of gravity fields except for the positively linear case. Further, by varying the gravity fields, one can witness shifts in the chaotic and periodic regimes. Moreover, the before- and after-effects of going through a periodic regime are examined. In the absence of the gravity variation parameter, the results of the constant-gravity problem are recovered. Ultimately, the rectangular enclosure is studied as a limiting case of the cylindrical enclosure problem. 2026 World Scientific Publishing Company.