Journal of Advances in Mathematics and Computer Science

Modelling Quarantine in Monkeypox Virus Transmission: A Critical Appraisal of Construct Definition, Parameter Evidence and Policy Inference

P. O. Aye, P. O. Olatunji, F.T. Daodu, O. J. Olatubi, S. A. Jegede — Wed, 29 Jul 2026 00:00:00 +0000

Quarantine occupies an unusual position in the quantitative literature on mpox. It is among the most frequently simulated control measures in transmission models of monkeypox virus (MPXV), yet it is among the least precisely specified. The 2022 multi-country outbreak driven by clade IIb, and the subsequent expansion of clade I transmission in central and eastern Africa, prompted a rapid proliferation of compartmental, network and individual-based models in which a quarantine class or a quarantine rate is used to represent the removal of exposed or infectious individuals from effective contact. This review examines how the quarantine construct has been defined, parameterised, calibrated and interpreted across that literature, and asks whether the resulting policy claims are supported by the evidence on which they rest. Literature was identified through structured searches of accessible scholarly indexes and metadata services, supplemented by backward and forward citation searching and by consultation of authoritative institutional sources, and was appraised against criteria covering construct validity, structural assumptions, parameter provenance, calibration, uncertainty treatment and inferential logic. Six critical findings emerge. Quarantine of exposed contacts and isolation of symptomatic cases are routinely conflated, so that reported effect sizes refer to different interventions under a single label. Deterministic homogeneous-mixing architectures dominate, although MPXV transmission is strongly overdispersed and network-structured. Quarantine parameters are typically assumed rather than estimated, and sensitivity analyses are frequently conducted over invented rather than empirical ranges. The recurrent result that raising the quarantine rate reduces the reproduction number is largely a structural consequence of model formulation rather than an empirical discovery. Data-anchored analyses reach substantially more conditional conclusions than parameter-sweep analyses. Empirical evaluations of isolation and contact tracing report weak certainty of effect and substantial operational failure, particularly in endemic settings. Quarantine effectiveness is contingent on clade, transmission route, detection delay and adherence, and models that omit these contingencies overstate what quarantine can achieve. Priorities include construct standardisation, joint estimation of detection and isolation delays, and explicit representation of adherence and equity constraints.

A Unified Quantum–Classical Framework for BER Analysis of Different Modulations under AWGN and Fading Channels

Aahana Nischal, Arav Jha, Nikhilesh Rao, R. Bhagya, K. Saraswathi — Fri, 17 Jul 2026 00:00:00 +0000

Reliable communication under additive noise, multipath fading, and mobility-induced channel variation remains a central requirement in contemporary wireless systems. This study develops a unified quantum-classical framework for examining bit error rate (BER) performance across ideal and impaired channel conditions. The classical component models orthogonal frequency-division multiplexing with BPSK, QPSK, 8-PSK, and 4-, 16-, 64-, and 128-QAM using MATLAB R2026a. The quantum-proxy component is implemented in Qiskit 2.3.0 using computational-basis qubits and Kraus-operator models for bit-flip, amplitude-damping, and phase damping noise. BER is evaluated against signal-to-noise ratio (SNR) for additive white Gaussian noise and combined fading and Doppler conditions. The classical results show a consistent reduction in BER as SNR increases, with BPSK exhibiting the greatest robustness and higher-order PSK and QAM schemes showing greater sensitivity to channel impairment. In the quantum-proxy simulation, BER remains largely independent of the number of bits represented per symbol because each qubit is encoded and measured as an independent binary state. Phase damping has negligible influence on computational-basis measurement outcomes, whereas bit-flip and amplitude-damping processes principally determine the observed errors. The numerical BER values from the two frameworks are not directly comparable because the quantum SNR axis represents a proxy mapping to noise probabilities rather than a calibrated physical Eb/N0 measure. The framework therefore supports a qualitative comparison of error mechanisms while clarifying the present limitations of basis-state quantum encoding for modelling higher-order modulation.

Theoretical Study on Spatial Ring Formation and Stabilization of Spatiotemporal Solitons

V. Sabeer, N. K. Hashim, A. K. Shafeeque Ali — Sat, 11 Jul 2026 00:00:00 +0000

Spatiotemporal solitons become dynamically unstable in an unbalanced nonlinear medium. This study examines the conditions that enable stable propagation in both negative-index and positive-index regimes of metamaterials (MMs). Using Lagrangian variational analysis and the split-step Fourier method, we show that three-dimensional light bullets remain stable under specific conditions. In the negative-index regime, stability occurs when normal dispersion balances defocusing cubic and focusing quintic nonlinearities. In the positive-index regime, stability arises when anomalous dispersion interacts with focusing cubic and defocusing quintic nonlinearities. We also observe the formation of spatial rings during the propagation of a Gaussian beam in certain regimes of nonlinearity and dispersion. These results provide new insight into soliton dynamics in MMs and may enable applications in optical communications, photonics, and nonlinear optics.

Switching-Algebraic Evaluation of All-Terminal Reliability of a Computer-Communications Network: A Karnaugh-Map Perspective

Fri, 17 Jul 2026 00:00:00 +0000

Network reliability is a fundamental measure for assessing the ability of a network to maintain successful connectivity under component failures. In computer-communications networks, reliability evaluation depends on whether all nodes remain mutually connected despite edge failures. This paper presents a Boolean-based framework for evaluating the all-terminal reliability of bidirectional networks. Network success and failure are formulated as coherent switching functions of independent edge success indicators, and their probabilistic expectations are obtained through the Probability Transform after deriving probability-ready expressions. The proposed approach integrates path-set, spanning-tree, and cut-set methods within a unified switching-algebraic setting. The all-terminal success is expressed as the conjunction of selected two-terminal successes and, equivalently, as a disjunction of spanning trees, whereas the all-terminal failure is represented through a disjunction of vertex cut-sets. Regular Karnaugh maps are used to visualise coherence, absorption, complementation, prime implicants, and disjointness, while variable-entered Karnaugh maps are used to provide compact factored representations that preserve statistical independence and facilitate the derivation of probability-ready expressions. The methodology is demonstrated for a running example of a five-node, seven-edge network. For this example, the all-terminal success function comprises 21 spanning trees and is shellable, whereas the complementary failure function comprises only 10 vertex cut-sets and is non-shellable. The case of components with equal reliabilities is further examined through the derivation of reliability and unreliability polynomials, comparison with related k-out-of-n systems, and identification of the lower boundary of useful redundancy. The results indicate that Boolean algebra and Karnaugh-map techniques provide a transparent, pedagogical, and effective approach for network reliability computation and visualization.

Nonlinear Radiation-induced Magneto-bioconvective Transport in a Casson Nanofluid with Double Stratification and Velocity Slip Over a Stretching Surface

Liberty Ebiwareme, Kubugha Bunonyo Wilcox, Fun-Akpo Kormane Pere — Wed, 22 Jul 2026 00:00:00 +0000

The steady two-dimensional magnetohydrodynamic boundary-layer flow of a non-Newtonian Casson nanofluid past a stretching surface, in the presence of velocity slip, thermal radiation, and bioconvection effects, is investigated in this study. The mathematical model incorporates the influences of Brownian motion and thermophoresis within the Buongiorno nanofluid framework, along with the dynamics of gyrotactic microorganisms. The governing nonlinear partial differential equations for momentum, energy, nanoparticle concentration, and microorganism density are formulated and transformed into a system of coupled ordinary differential equations using appropriate similarity transformations. The transformed system is solved numerically using the Adomian Decomposition Method. The effects of key physical parameters, including the Casson parameter, magnetic field strength, slip parameter, thermal radiation parameter, Brownian motion parameter, thermophoresis parameter, and bioconvection Lewis number, on the velocity, temperature, concentration, and microorganism density profiles are analysed in detail. The results reveal that increasing the magnetic parameter significantly suppresses the fluid velocity due to the Lorentz force, while enhancing thermal and concentration boundary-layer thicknesses. The presence of velocity slip is found to reduce surface shear stress, whereas thermal radiation intensifies the heat transfer rate within the boundary layer. Furthermore, the parameters of Brownian motion and thermophoresis play a crucial role in augmenting nanoparticle distribution, while bioconvection effects significantly influence microorganism density profiles. Engineering quantities of practical interest, such as the skin friction coefficient, local Nusselt number, Sherwood number, and motile microorganism density number, are computed and discussed. The present study provides insight into the relationship between magnetic fields, non-Newtonian behaviour, nanoparticle transport, and bioconvection, with potential applications in biomedical engineering, microfluidic devices, and advanced cooling technologies.

Performance of Misbalance Adriatic Topological Indices in QSPR Modeling of Nonsteroidal Anti-inflammatory Drugs

Bharathi Shettahalli Nagaraje Urs — Wed, 29 Jul 2026 00:00:00 +0000

Misbalance Adriatic topological indices quantify differences between the degrees of adjacent vertices and may serve as molecular descriptors in quantitative structure-property relationship (QSPR) modelling. This study evaluated the predictive performance of four such indices—the misbalance deg index (MD), misbalance rodeg index (MRD), misbalance irdeg index (MIRD), and misbalance haddeg index (MHD)—for selected nonsteroidal anti-inflammatory drugs (NSAIDs). The indices were computed from hydrogen-suppressed molecular graphs and examined in relation to six physicochemical properties: boiling point, polarizability, complexity, refractivity, molecular weight, and molar volume. Pearson correlation coefficients were used to assess linear associations, and separate simple linear regression models were developed for each descriptor-property combination. All four indices showed positive correlations with the investigated properties. Polarizability and refractivity generally exhibited the strongest associations, whereas molar volume showed weak correlations across all descriptors. MD provided the strongest overall regression performance and the highest coefficients of determination for boiling point, complexity, and molecular weight. MRD performed best for polarizability and refractivity, while MHD produced the highest coefficient of determination for molar volume, although this model remained weak. MIRD and MHD yielded broadly comparable results for the remaining properties. The findings indicate that the investigated indices may support preliminary QSPR estimation within the analysed NSAID dataset, while their predictive utility requires further assessment using larger datasets and additional modelling approaches.

On Multifunctions in Ideal Topological Space

M. V. Sangeetha — Sat, 01 Aug 2026 00:00:00 +0000

Aims: This study introduces and examines upper and lower R−I−continuous multifunctions in ideal topological spaces. It also considers two weaker variants, namely upper and lower almost R−I−continuous multifunctions and upper and lower weakly R−I−continuous multifunctions.

Study Design: The investigation is theoretical.

Place and Duration of Study: The work was conducted in the Department of Mathematics, St. Joseph’s College (Autonomous), Devagiri, Calicut, India.

Methodology: Logical deduction was used to derive definitions, equivalence conditions, theorems, and related consequences from established concepts in topology and ideal topological spaces.

Results: Characterisations of upper and lower R−I−continuity were obtained in terms of inverse images, R−I−open and R−I−closed sets, neighbourhoods, closures, interiors, graph multifunctions, compactness, connectedness, and the R−I−kernel. The behaviour of compositions was examined in detail, and conditions connecting the continuity of a multifunction with that of its graph multifunction were established. The study also characterised the almost and weak forms of R−I−continuity and clarified the implication relations among the introduced classes.

Conclusion: The results provide a unified theoretical treatment of upper and lower R−I−continuous multifunctions and their almost and weak variants within a single ideal-topological framework. The established characterisations and implication relations may support further theoretical investigations of generalised continuity in ideal topological spaces.

Asymptotic and Oscillatory Behaviour of First-Order Neutral Difference Equations With Non-Monotone Advanced Arguments

D. Palanisamy, A. Murugesan — Sat, 01 Aug 2026 00:00:00 +0000

This paper studies the oscillatory and asymptotic behaviour of a class of first-order nonlinear neutral difference equations with non-monotone advanced arguments of the form

\(\begin{equation}
\Delta\left[\Theta(\vartheta)-\sum\limits_{i=1}^r \rho_i(\vartheta) \Theta\left(\tau_i(\vartheta)\right)\right]-\sum\limits_{i=1}^k \phi_i(\vartheta) g_i\left(\Theta\left(\varphi_i(\vartheta)\right)\right)=0 ; \quad \vartheta \geq \vartheta_0 .
\end{equation}\) (a)

Using appropriate comparison methods, auxiliary sequences, and exponential inequalities, new sufficient conditions are established for the oscillation and convergence to zero of all solutions of the equation under investigation. Auxiliary lemmas are proved to examine the asymptotic characteristics of eventually positive and eventually negative solutions, and improved oscillation criteria are established in terms of the limit inferior and limit superior associated with equation (a). The obtained results improve and extend several known oscillation theorems in the literature by allowing multiple non-monotone advanced arguments and nonlinear neutral terms under weaker hypotheses.