Kanban is a pull-based workflow management methodology designed to improve delivery efficiency by limiting the number of tasks that may be processed concurrently within an execution pipeline. Its defining operational mechanism is the enforcement of a work-in-progress limit, which constrains the number of active tasks, mitigates excessive task accumulation, and promotes continuous workflow. Despite its widespread industrial adoption, a rigorous stochastic characterization of Kanban pipeline dynamics under finite work-in-progress constraints has remained limited. In this study, the Kanban workflow was formulated as a finite-capacity birth-death process, where the pipeline capacity was determined by the work-in-progress limit and the state space was truncated by a closed boundary condition. System behavior is characterized by the traffic intensity, defined as the ratio of the task arrival rate to the task service rate, thereby providing a quantitative measure of resource utilization and pipeline congestion. To evaluate the structural uncertainty of workflow evolution, an information-theoretic framework was established by introducing the information associated with each pipeline state and the corresponding entropy. In addition, closed-form analytical expressions are derived for the expected number of tasks within the execution pipeline, the pipeline entropy, and the average system lead time experienced by successfully admitted tasks. The effects of both system utilization and the work-in-progress limit on these performance measures were analytically quantified, thereby revealing the fundamental trade-offs between throughput, congestion, operational uncertainty, and delivery responsiveness. The proposed formulation provides a unified probabilistic and information-theoretic perspective for analyzing constrained workflow systems, and establishes a theoretical foundation for quantitatively evaluating Kanban performance and optimizing work-in-progress policies across knowledge-intensive project environments.
Nonlinear electrostatic potential waves play a fundamental role in determining the transport characteristics, energy localization, and stability of magnetized plasma generated within rocket engine exhaust plumes. Their propagation is effectively described by the modified Zakharov–Kuznetsov equation, in which the nonlinear and multidimensional dispersive coefficients are governed by key plasma parameters, including electron temperature, ion density, Debye length, and ion Larmor radius. An advanced computational solution framework, constructed through a unified wave transformation coupled with an auxiliary ansatz method, was employed to derive exact traveling-wave solutions of the governing nonlinear partial differential equation. Fifteen exact analytical solutions were obtained and systematically classified according to the discriminant parameter ($t$), thereby providing a comprehensive description of the nonlinear wave dynamics. For $t >$ 0, multiple localized solitary-wave structures, including bright solitons, dark solitons, and singular solitons, were identified, demonstrating stable electrostatic energy localization within magnetized exhaust plasma. For $t <$ 0, periodic wave trains and curved periodic wave surfaces were generated, indicating oscillatory electrostatic potential distributions associated with potential high-frequency plasma instabilities that may influence nozzle-flow behavior. When $t$ = 0, rational solutions were obtained, representing localized electrostatic potential spikes. The influences of plasma density and external magnetic field strength on wave amplitude, propagation velocity, and waveform evolution were further examined through three-dimensional surface visualizations. The analytical solutions provide rigorous benchmark results for validating numerical simulations of nonlinear plasma dynamics while offering theoretical insight into electrostatic wave evolution in magnetized propulsion environments. The proposed solution framework also establishes a reliable mathematical foundation for the predictive analysis of plasma-wall interactions, optimization of thrust performance, mitigation of plasma-induced instabilities, and the development of next-generation electromagnetic and plasma-based propulsion technologies.
Herpes simplex virus type 2 (HSV-2) is a persistent sexually transmitted infection (STI) with important public health implications, particularly among female sex workers (FSWs), where recurrent infection, asymptomatic shedding, and behavioral risk factors contribute to sustained transmission. This study develops a $\psi$-Hilfer fractional mathematical model for HSV-2 transmission dynamics to incorporate memory, hereditary effects, and nonlocal temporal dependence that cannot be fully captured by classical integer-order models. The proposed framework extends an existing HSV-2 transmission model by formulating the system with the $\psi$-Hilfer fractional derivative and analyzing its qualitative and numerical properties. We establish the existence, uniqueness, non-negativity, and boundedness of solutions within a biologically feasible region. The basic reproduction number is derived to characterize threshold behavior, and local and global stability analyses are performed for disease-free and endemic equilibria. In addition, an optimal control problem is formulated to evaluate prevention education, antiviral treatment, and behavioral intervention strategies. Necessary optimality conditions are obtained using fractional optimal control theory. Numerical simulations are carried out using the Adams–Bashforth–Moulton predictor–corrector method (ABM–PECE) under different fractional orders, type parameters, and kernel functions. The results demonstrate that the $\psi$-Hilfer fractional framework provides a flexible and biologically meaningful representation of HSV-2 persistence, delayed stabilization, and intervention response. Overall, the findings suggest that memory-based fractional modeling can improve predictive interpretation, stability characterization, and control design for HSV-2 transmission, especially in high-risk populations where historical exposure and recurrent infection play central roles.
Rapid marriage and breakups remain a pressing social concern, impacting everything from social development to child welfare and family unity. While social and behavioral sciences are focusing on the gradual shift from marital discord to infidelity and, ultimately, divorce, there is a lack of quantitative mathematical models that could effectively explain these interconnected processes. This study delved into the dynamics of marital instability through a deterministic Conflict–Adultery–Divorce–Reconciliation (CADR) mathematical model, which brought together various elements spread by conflicts including the emergence of infidelity, divorce, reconciliation, economic pressures, and social influences. To ensure both biological and mathematical soundness, key quality attributes were incorporated into the model, such as positive, boundless, and the existence and uniqueness of solutions. This paper assessed how different model parameters influenced reproduction numbers through normalized sensitivity analysis. Numerical simulations, using the fourth-order Runge–Kutta (RK4) method, revealed that enhancing reconciliation and conflict resolution could effectively curbs the spread of issues and promote long-term marital stability. Conversely, increase in conflict transmission, economic stress, social influence, and progression of both infidelity and divorce significantly heightened marital instability. Sensitivity analysis indicated that reconciliation and conflict resolution were the most effective stabilizing strategies, while conflict transmission stood out as the leading cause of marital instability. This proposed model not only laid a theoretical groundwork for evaluating intervention strategies aimed at strengthening marriages but also provided a robust mathematical framework for understanding the complex interplay between conflict, infidelity, divorce, and reconciliation.
The scheme of the proposed method, reduced differential transformed method (RDTM), provided the solution of time-dependent fractional reaction-diffusion models. Reaction-diffusion systems often appear in the modeling for an essential basis of the processes of morphogenesis in the field of biology (and may even be observed in skin pigmentation and animal coats), for pattern formation of a prototype model (like spirals, fronts, targets, stripes, hexagons, and dissipative solitons), including the spread of epidemics, ecological invasions, wound healing, and tumor growth. In this study, the behavior and analytical treatment of nonlinear time-dependent fractional Cauchy reaction-diffusion partial differential equations (CRDPDE) have been studied via the scheme of RDTM. The finding was interesting to reveal that the scheme was and consistent for the solutions to the problems concerned. The present study suggests that RDTM is simpler and more easily calculable than other methods, hence applicable to any coupled systems.
An optimal homotopy asymptotic framework is developed for the numerical-semi-analytical treatment of the time-dependent generalized Korteweg–de Vries (KdV)-modified gKdV-mKdV equation, a prototypical nonlinear dispersive model featuring concurrent quadratic and cubic nonlinearities. The equation arises widely in optics, fluid mechanics, plasma physics and condensed-matter systems, where the accurate resolution of solitary waves and complex wave interactions is essential. The Optimal Homotopy Asymptotic Method (OHAM) is formulated without reliance on an artificial small parameter and is equipped with optimally selected convergence-control parameters, thereby overcoming limitations of classical perturbation techniques. Within this formulation, a rapidly convergent approximate analytical solution is constructed, and error dynamics are quantified against benchmark solutions. Comparative assessments indicate that OHAM attains high accuracy with modest computational effort, delivering pointwise errors and global norms that are competitive with, or superior to, those obtained by Homotopy Perturbation and Homotopy Analysis methods. The procedure is straightforward to implement, preserves the dispersive-nonlinear balance intrinsic to the gKdV–mKdV dynamics, and accommodates important special cases (KdV and mKdV limits) within a unified treatment. The approach is thus shown to provide a reliable and easily computable route to soliton-bearing solutions and other nonlinear waveforms, supporting applications in waveguides, shallow-water channels, ion-acoustic media and lattice excitations. The methodological clarity and demonstrated accuracy suggest that OHAM can serve as a practical front-line tool for nonlinear PDEs with mixed nonlinearities and higher-order dispersion, and that its convergence-control strategy can be extended to related integrable and near-integrable models.
To investigate the dynamic response and potential structural degradation of carbon fiber sucker rod strings during operation, a torsional vibration model incorporating helical buckling-induced torque excitation has been developed. In this model, the upper suspension boundary condition is idealized as a torsional spring, whose stiffness is determined as a function of both axial displacement and applied load at the suspension point. The torsional stiffness is categorized into time-dependent and mean (average) components, both of which are examined through numerical simulation using the finite difference method. The results reveal pronounced torsional oscillations at the upper section of the rod string, indicating significant torsional deformation of the suspension assembly. A non-monotonic relationship is observed between stroke length and vibration amplitude, wherein torsional vibration initially intensifies with increasing stroke before attenuating, suggesting the presence of resonance phenomena within specific operational ranges. The simulations further demonstrate that time-varying and average torsional stiffnesses yield comparable influences on the overall torsional response. Helical buckling deformation is shown to play a critical role in amplifying torsional stress, with the induced torque predominantly localized in the mid-to-lower segments of the wellbore. The presented model provides an essential theoretical framework for understanding the complex interaction between axial deformation and torsional instability, offering new insights into the mechanisms that may precipitate longitudinal splitting or fatigue failure in carbon fiber sucker rod strings. These findings are expected to support the optimization of rod string design and operational strategies in advanced artificial lift systems.
This study presents a vibrational analysis of an elastic bar, a fundamental element in continuous systems. The primary objective is to evaluate the vibrational response of a uniform elastic bar under various boundary conditions, including Dirichlet, Neumann, and mixed types. Both numerical and analytical techniques—specifically the finite element method (FEM) and the method of separation of variables—are employed to determine the eigenfrequencies and mode shapes of the bar. The governing equation for a uniform torsional bar, along with its natural boundary conditions, is formulated and solved using separation of variables, leading to coupled equations. Solutions are derived for multiple end conditions, and dispersion (frequency) equations are obtained to compute the eigenvalues. Root-finding methods are used to extract natural frequencies and corresponding eigenfunctions. The vibrational response is visualized for different cases and compared with existing results in the literature. Findings reveal that the natural frequencies of torsional bars are affected by additional elements such as attached masses, springs, and dampers. This investigation enhances the understanding of elastic bar dynamics and provides useful insights for the design and optimization of structural systems involving torsional bars.
Automobiles play a vital role in daily life, providing suitable and efficient transportation for work, school, and errands. They also support essential services like emergency response, goods delivery, and public transportation systems. This increased variety means that car manufacturers are competing intensely to attract customers and maximize their profits. However, making the right choice when buying a car can be challenging due to the wide range of factors to consider. This study introduces a new approach that uses Dombi operators combined with T-spherical fuzzy numbers (T-SFNs) to help improve the decision-making process. This method reduces the uncertainty and imprecision that often comes with decision-making, especially when selecting a car. The aim is to help customers make better, more informed choices and avoid financial difficulties. To achieve this, the study develops several innovative operators namely T-spherical fuzzy Dombi weighted averaging (T-SFDWA), T-spherical fuzzy Dombi ordered weighted averaging (T-SFDOWA), T-spherical fuzzy Dombi weighted geometric (T-SFDWG), T-spherical fuzzy Dombi ordered weighted geometric (T-SFDOWG). These methods offer flexibility, suppleness and can adapt to real-world problems where factors are constantly changing. By managing uncertainty and hesitation effectively, these approaches help decision-makers evaluate complex situations with multiple variables. A practical example, such as choosing a car, demonstrates how these approaches can evaluate important criteria like price, safety, and fuel efficiency. Ultimately, these methods ensure that consumers can make the best decision, even in uncertain and complex situations.
Neutrosophy is a special area of philosophy that explains the nature, genesis and scope of neutralities, like the interactions with diverse ideational hues. It showed the degree of indeterminacy as an independent component that was the extension of an intuitionistic set. In this paper, the interpretation of the linear equation of type $\mathcal{A}\mathcal{X} +\mathcal{B} =\mathcal{C}$ are discussed in a neutrosophic environment. It is observed that the equations $\mathcal{A}\mathcal{X} +\mathcal{B} =\mathcal{C}$, $\mathcal{A}\mathcal{X} =\mathcal{C} -\mathcal{B}$ and $\mathcal{A}\mathcal{X} -\mathcal{C} =-\mathcal{B}$ are same and their solution are also same in crisp sense. But, in the neutrosophic sense, the solutions to the above equations are different. Mathematical operations on intervals are considered for the purpose of solution and analysis. Further, an application of budgeting-financing is described with the help of neutrosophic fuzzy equation.
Accurate and robust image segmentation remains a fundamental challenge in computer vision, particularly in the presence of intensity inhomogeneity, noise, and weak object boundaries. To address these challenges, we propose a Robust Pythagorean Fuzzy Energy-Based Level Set (RPFELS) model, which integrates a novel fuzzy energy formulation with level set evolution to enhance segmentation precision and resilience against noise. The model introduces a Pythagorean fuzzy divergence term to refine energy optimization, ensuring adaptive boundary preservation and reducing sensitivity to intensity variations. Additionally, a bounded fuzzy energy constraint is incorporated to ensure numerical stability and prevent energy leakage during evolution. Extensive experiments on benchmark datasets, including medical and natural images, validate the effectiveness of RPFELS. The model consistently outperforms recent selective segmentation methods in terms of Dice Score, Jaccard Index, and Hausdorff Distance, achieving superior segmentation accuracy and reduced boundary errors. Furthermore, a detailed statistical significance analysis using paired t-tests confirms that the observed improvements are statistically significant (p-value $<$ 0.01), reinforcing the reliability of the proposed approach. Moreover, RPFELS exhibits higher computational efficiency, achieving faster convergence rates compared to existing methods. These findings highlight the robustness and versatility of the proposed approach in handling challenging segmentation scenarios, making it suitable for applications in medical imaging, remote sensing, and industrial defect detection. By ensuring bounded energy evolution and statistically validated performance gains, our model sets a new benchmark in selective segmentation.
In order to approximate several roots of nonlinear equations, we presented a novel family of two-step optimal iterative methods in this study. The method is fourth-order convergent, requiring just four function evaluations each iteration, and it is optimal in terms of Kung-Traub's conjecture. We use complex dynamical analysis, often known as basins of attraction, to study local convergence and dynamical behavior. Numerical experiments on nonlinear problems in biomedical engineering are carried out to determine the method's efficiency and robustness in comparison to other methods. In terms of convergence rate, computational complexity, and stability, numerical findings show that the novel approach outperforms the well-known existing algorithms, especially for functions with higher multiplicities of order.