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We present a mathematical model for the slow combustion (smoldering) of a two-dimensional sheet of paper. We describe the evolution of the char region, and we investigate the effects of an orthogonal air flow on the shape of the combustion front. The mathematical formulation consists in a set of two nonlinear PDEs for the temperature and the oxygen concentrations coupled with one ODE for the cellulose concentration. The (dimensionless) problem is solved numerically by means of a spectral collocation scheme based on Chebyshev polynomials. Our results show that the Péclet and the Lewis number strongly influence the shape of the ignition front and that the advancement of the combustion front does not occur if advection and diffusion are neglected (zero Péclet and Lewis numbers). In particular we observe that the burning region and the ignition front are strongly influenced by the velocity of the airflow and by the mass and heat transport phenomena due to diffusion and advection. We shall see that the increasing of the ratio between the convective and diffusive characteristic times (Péclet number) and the decreasing of the ratio between the mass and heat diffusive characteristic times (Lewis number) have a "flattening effect" on the combustion front. [ABSTRACT FROM AUTHOR]

In this article, we present a mathematical model and numerical simulation of the coffee-ring effect on porous papers. The numerical method is based on Monte Carlo simulation. The proposed model is simple but can capture the main mechanism of coffee stain formation on porous papers. Several numerical experiments are presented to demonstrate the performance of the proposed algorithm. We can obtain the coffee-ring effect on porous papers as the computer simulation results. [ABSTRACT FROM AUTHOR]

The quest for cost-effective and thermal efficient structural materials onto beating the high cost of construction is gaining more attention among researchers. This study focused on the blending of cement and sand with waste paper pulp into cost-effective structural materials. The composites were prepared in four mix groups with each containing a fixed amount of sand at 5, 10, 15, and 20 wt.% (by weight of pulp). Cement was varied at 10, 20, 30, and 40 wt.% in each group, and curing was done for 28 days. Properties evaluated are compressive, bending, and splitting strengths. It was observed that increasing cement and sand contents enhanced strengths; howbeit, the blend of 30 wt.% cement/15 wt.% sand resulted in a reduction in bending strength even as 30 wt.% cement/20 wt.% sand engendered a decrease in bending and splitting strength. The microstructural features showed that inherent fibers of the pulp were well bonded with hydration products and sand content yielding good performance in the composites. The optimization procedure carried out depicted a combination of 35.27% cement and 20% sand as the optimum composition. Experimental outcomes were modelled for the purpose of prediction of responses. The models were confirmed statistically fit showing how varying cement content affected strength responses at fixed sand proportion. ANOVA affirmed the significant contribution of cement and sand on the strength responses. Compliance reliability was observed to be dependent on the interactive pattern between cement and sand. Going by the standard prescription for the strength properties, cement and sand content of 35.27 and sand 20 wt.% satisfied all strength requirements for low-cost construction having a compliance reliability of 1.31. [ABSTRACT FROM AUTHOR]

Industrial progress in papermaking in the early nineteenth century led to the technologies that resulted in more acidic papers, which was caused mainly by the exploitation of alum (KAl(SO4)2) and rosin as sizing agents. The papers prepared by such technologies have degraded more quickly. From the 1930s various deacidification and preservation processes with basic agents have been developed. The most widespread deacidification process is with the aerosol (spray system) consisting of microscale particles MgO and perfluoroheptane (PFH) as a carrier (the so-called Bookkeeper process). The shortcomings of this process are the low dissolution of solid MgO particles and the transport to the interior of acidic paper. We have developed a theoretical two-level model of the Bookkeeper process suitable for prediction of deacidification extent. The model involves both the dissolution/reaction of the solid particles and transport of solvated ions and solid particles inside the bulk of paper. The developed model coincides with the results of the performed deacidification experiment. The model is also in good agreement with the Lucas–Washburn equation, which is usually used for the description of the penetration of a deacidifying agent into the paper. [ABSTRACT FROM AUTHOR]

Purpose: The mounted stationary sensor on the ring casing has become a widely accepted way to monitor the planetary gear condition and one challenging aspect of this method is the modulation effect caused by the moving planet gears. It is valuable to study the modulation effect caused by the moving planet gears. Method: Different window functions have been proposed to model this modulation phenomenon and there are several drawbacks: the selection of the window function parameters is often arbitrary and subjective instead of basing on the planetary gear physical parameter; the current window function is hard to reflect the impact from the ring gear boundary conditions. Therefore, this paper simulated this modulation phenomenon as moving load dynamic problem to overcome these drawbacks, where the ring casing has been modelled as an axisymmetric flexible structure and the internal meshing forces have been modelled as spatially varying moving loads. Based on the improved hamming window function, this paper related the window function parameters with the planetary gear physical properties and operation conditions and then, quantified the modulation effect with the consideration of moving load speed as well as the ring gear boundary condition. Results: For the planetary gear carrier arm rotation speed, the result suggested that the moving speed mainly affect the parameter β and the corresponding value showed a nonlinear decreasing trend when the moving speed increased. For the ring gear rim thickness, similarly, parameter β increased significantly with the increase of the rim value. For the radial support stiffness, parameter β has also been affected most and it shows a decreasing trend when the support stiffness increased. For the sensor location, both parameter α and β shows a periodical change around the ring casing. Conclusion: The results suggested that both parameters have been impacted by the rotation speed and boundary conditions, among which parameter β has been impacted most. [ABSTRACT FROM AUTHOR]

Photoacoustic (PA) medical imaging is a crossbred technique relying on light-induced ultrasonic waves due to the PA effect phenomenon recorded primarily in 1880 by A. G. Bell. Numerical simulation, also known as in-silico, studies assist scientists in minimizing incorrect PA experiments in both in-vitro and in-vivo. Numerical modeling techniques help to achieve a fast simulation process in contrast to pure mathematics alone. However, if a suitable facilitated mathematical model can be established prior to applying numerical modeling, it will be of great interest to the whole numeric model. Numerous mathematical equations, theorems, and propositions have been proposed to model the whole PA signal generation and propagation process in biological media. However, most of them are complicated and difficult to be understood by researchers, especially beginners. That's why this paper was introduced. Our paper aims to simplify the understanding of the generation and propagation process of biomedical PA waves. We have developed a facilitated mathematical model for the entire process. The introduced developed mathematical model is based on three steps: (1) pulsed laser stimulation, (2) light diffusion, and (3) PA stress wave generation and propagation. The developed mathematical model has been implemented utilizing COMSOL Multiphysics, which relies on the finite element method (FEM) numerical modeling principle. The in-silico time-dependent study's results confirmed that the proposed mathematical model is a simple, efficient, accurate, and quick starting point for researchers to simulate biomedical PA signals' generation and propagation process utilizing any suitable software such as COMSOL multiphysics. [ABSTRACT FROM AUTHOR]

The paper presents a brief analytical review of the current state of research in the field of recovery and its modeling in order to predict the structure and properties, as well as a review of experimental research methods and mathematical models of the processes of structure formation during annealing of cold-rolled steels. The paper also presents the results of an experimental study of the recovery process in cold-rolled automotive steels using various techniques and describes a mathematical model for calculating the kinetics of this process depending on the temperature and chemical composition of steels. [ABSTRACT FROM AUTHOR]

This paper deals with developing a versatile electronic emulator (EE) of a wind generating system (WGS) that does not use rotating machines, which can be used for research development and educational tools. Thus, the proposed EE platform represents a cost-effective alternative to perform research (tests and analyses) and facilitate academic learning and teaching. The association of a permanent magnet synchronous generator with a wind turbine mathematical model is virtually implemented to compose the aerogenerator. A reference generator system (RGS) generates the control references employed to control the actual back-to-back converter, composed of a controlled rectifier and a current-controlled voltage source inverter (VSI), connected to the power grid and sharing the same DC bus. From the RGS, the power generated by the virtual aerogenerator is used to calculate the current references drained from the grid by the controlled rectifier. The VSI controls the DC bus voltage and injects it into the power grid sinusoidal current, emulating a complete WGS. Besides the power converters' transfer functions and the DC bus control in the dq synchronous reference frame, a graphical interface (GI) platform is implemented. The proposed EE-WGS is validated through simulation and experimental results, while the electrical quantities can be visualized using the GI to assist in evaluating the WGS static and dynamic behaviors with a full-scale back-to-back power converter. [ABSTRACT FROM AUTHOR]

The present paper aims to introduce a constructivist narrative intervention for Narrative Identity Reconstruction (NIR) in working with clients with a history of stressful life events (SLE). This intervention is based on a proposed conceptual framework explaining how SLE affects narrative identity. First, we provide a conceptual model to show the theoretical links between SLE and narrative identity through the three functions of making meaning, unity, and purpose. The present conceptualization proposes that concepts of meaning-making, self-concept clarity, and agency should improve for narrative identity reconstruction. For designing therapy steps, we were inspired by the procedure of the Life Design process for reconstructing narrative identity. We defined the following steps: (a) construct self-story through small stories, (b) deconstruct these stories, (c) reconstruct them into an identity narrative or life portrait, and (d) co-construct intentions that lead to the next action episode in the real world. We hope NIR can help clients construct a robust self-narrative in which the SLE is not a confusing and distressing experience leading to a broken narrative; instead, it can make sense and integrate into the bigger picture of self-narrative. It is suggested that future research empirically examine the NIR to explore the feasibility and effectiveness of the intervention in mental health settings. [ABSTRACT FROM AUTHOR]

In this paper, a practical scenario of multicasting through heterogeneous cellular network has been considered. The macro base station of macro cell transmits confidential information to its intended multicast macro users and multiple eavesdroppers try to decode this information and pico base station of pico cell transmits confidential information to its intended multicast pico users. Authors are interested to develop a mathematical model consists of the closed-form analytical expression for the secrecy multicast capacity (SMC) to protect that confidential information from eavesdropping. The results show that the simultaneous effects of double scatterer and correlation significantly reduce the security in multicasting but these reduction in the security can be compensated by antenna diversity at the multicast users. The results also show the effect of double scatterer on different correlation scenario (Constant Correlation and Jakes Correlation) in terms of the correlation figures of transmit, receive and scatterer correlation matrices. [ABSTRACT FROM AUTHOR]

This paper studies a mathematical model of the phase transition process as a moving boundary problem (MBP). An equation describing the temperature-dependent thermal conductivity and Robin-type boundary condition at the fixed boundary is used in the model. In order to solve the considered MBP, we propose an iterative-based Keller box method (KBM) for the numerical approximation and boundary immobilization method (BIM) to immobilize the moving boundary. In addition, KBM incorporates nonlinearities in thermal conductivity and boundary conditions. We study the stability and consistency and found out that the scheme is second-order accurate in both time and space. A specific case having a similarity solution has been considered to validate the numerical scheme. Our numerical results show that the KBM is in good agreement with the similarity solution. In addition, the rate of convergence of the KBM scheme is two. Different parameters and temperature-dependent thermal conductivity are studied to determine how these affect the position of the moving boundary. [ABSTRACT FROM AUTHOR]

With the continuous increase of mining in depth, the gas extraction faces the challenges of low permeability, great ground stress, high temperature and large gas pressure in coal seam. The controllable shock wave (CSW), as a new method for enhancing permeability of coal seam to improve gas extraction, features in the advantages of high efficiency, eco-friendly, and low cost. In order to better utilize the CSW into gas extraction in coal mine, the mechanism and feasibility of CSW enhanced extraction need to be studied. In this paper, the basic principles, the experimental tests, the mathematical models, and the on-site tests of CSW fracturing coal seams are reviewed, thereby its future research directions are provided. Based on the different media between electrodes, the CSW can be divided into three categories: hydraulic effect, wire explosion and excitation of energetic materials by detonating wire. During the process of propagation and attenuation of the high-energy shock wave in coal, the shock wave and bubble pulsation work together to produce an enhanced permeability effect on the coal seam. The stronger the strength of the CSW is, the more cracks created in the coal is, and the greater the length, width and area of the cracks being. The repeated shock on the coal seam is conducive to the formation of complex network fracture system as well as the reduction of coal seam strength, but excessive shock frequency will also damage the coal structure, resulting in the limited effect of the enhanced gas extraction. Under the influence of ground stress, the crack propagation in coal seam will be restrained. The difference of horizontal principal stress has a significant impact on the shape, propagation direction and connectivity of the CSW induced cracks. The permeability enhancement effect of CSW is affected by the breakage degree of coal seam. The shock wave is absorbed by the broken coal, which may hinder the propagation of CSW, resulting in a poor effect of permeability enhancement. When arranging two adjacent boreholes for CSW permeability enhancement test, the spacing of boreholes should not be too close, which may lead to negative pressure mutual pulling in the early stage of drainage. At present, the accurate method for effectively predicting the CSW permeability enhanced range should be further investigated. [ABSTRACT FROM AUTHOR]

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This manuscript delves into the examination of the stochastic fractional derivative of Drinfel'd-Sokolov-Wilson equation, a mathematical model applicable in the fields of electromagnetism and fluid mechanics. In our study, the proposed equation is through examined through various viewpoints, encompassing soliton dynamics, bifurcation analysis, chaotic behaviors, and sensitivity analysis. A few dark and bright shaped soliton solutions, including the unperturbed term, are also examined, and the various 2D and 3D solitonic structures are computed using the Tanh-method. It is found that a saddle point bifurcation causes the transition from periodic behavior to quasi-periodic behavior in a sensitive area. Further analysis reveals favorable conditions for the multidimensional bifurcation of dynamic behavioral solutions. Different types of wave solutions are identified in certain solutions by entering numerous values for the parameters, demonstrating the effectiveness and precision of Tanh-methods. A planar dynamical system is then created using the Galilean transformation, with the actual model serving as a starting point. It is observed that a few physical criteria in the discussed equation exhibit more multi-stable properties, as many multi-stability structures are employed by some individuals. Moreover, sensitivity behavior is employed to examine perturbed dynamical systems across diverse initial conditions. The techniques and findings presented in this paper can be extended to investigate a broader spectrum of nonlinear wave phenomena. [ABSTRACT FROM AUTHOR]

The Electronic Personal Health Record (EPHR) provides an innovative service for citizens and professionals to manage health data, promoting patient-centred care. It enhances communication between patients and physicians and improves accessibility to documents for remote medical information management. The study aims to assess the prevalence of awareness and acceptance of the EPHR in northern Italy and define determinants and barriers to its implementation. In 2022, a region-wide cross-sectional study was carried out through a paper-based and online survey shared among adult citizens. Univariable and multivariable regression models analysed the association between the outcome variables (knowledge and attitudes toward the EPHR) and selected independent variables. Overall, 1634 people were surveyed, and two-thirds were aware of the EPHR. Among those unaware of the EPHR, a high prevalence of specific socio-demographic groups, such as foreign-born individuals and those with lower educational levels, was highlighted. Multivariable regression models showed a positive association between being aware of the EPHR and educational level, health literacy, and perceived poor health status, whereas age was negatively associated. A higher knowledge of the EPHR was associated with a higher attitude towards the EPHR. The current analysis confirms a lack of awareness regarding the existence of the EPHR, especially among certain disadvantaged demographic groups. This should serve as a driving force for a powerful campaign tailored to specific categories of citizens for enhancing knowledge and usage of the EPHR. Involving professionals in promoting this tool is crucial for helping patients and managing health data. [ABSTRACT FROM AUTHOR]

The electronic, magnetic, mechanical, and other properties of crystalline substances are determined by their structure, i.e., by the periodicity and symmetry of the lattice; therefore, the determination of the structure is an important stage in the study of the characteristics of such materials. This paper considers a number of metals having a crystal lattice of the hexagonal closely packed (HCP) structural type: beryllium, cerium, cobalt, dysprosium, erbium, gadolinium, hafnium, holmium, lanthanum, lutetium, magnesium, neodymium, osmium, praseodymium, rhenium, ruthenium, scandium, terbium, titanium, thallium, thulium, yttrium, and zirconium. The application of the annealing simulation algorithm to find the metric parameters of the materials under consideration is shown using the close packing model, which is widely used in crystallographic calculations. The in-house software implementation of the simulated annealing algorithm presented in this paper allows us to determine the coordinates of the atoms included in the unit cell of the crystal lattice, as well as calculate the lattice constants and the packing density of atoms in the crystal cell of the HCP structural type using the given chemical formula and spatial symmetry group. These structural characteristics can be used as the input parameters in modeling the electronic, magnetic, and other properties of the considered materials. This paper compares the values of the crystal lattice constants obtained as a result of the numerical simulation with the published data. [ABSTRACT FROM AUTHOR]

In the mixed-model assembly line balancing and sequencing problem (MALBSP), workstations are assumed to be constantly available. The failure of any workstation will make the entire assembly line stop working. Preventive maintenance (PM) is a way to maintain the workstation before its failure, reduce unexpected downtime, and prolong its useful life. Previous studies have considered PM scenarios (PMS) in the simple and U-shaped assembly line to improve production efficiency and smoothness effectively, but not in the mixed-model assembly line. This paper fills this research gap, and the MALBSP considering PMS (MALBSP_PMS) is studied in this paper. A mixed-integer linear programming model is proposed to minimize makespan and task alteration. A migrating birds optimization algorithm is improved (IMBO) to obtain well-distributed Pareto frontier solutions. This algorithm designs a restart mechanism and an intra-population crossover operator to avoid falling into the local optimal and enhance its searchability. Experimental results demonstrate the effectiveness of two improvements and the IMBO algorithm. In addition, a real-world case study is introduced to illustrate the importance of considering PM scenarios in MALBSP. [ABSTRACT FROM AUTHOR]

The optimal construction of long-span ziplines represents a complex engineering and construction task, especially from a safety point of view. In contemporary literature and engineering practice, there are no appropriate theoretical bases, standards and recommendations directly related to this issue. The aim of this work is to try to define the appropriate theoretical and professional basis for the design of these devices. The paper describes the procedure for creating a mathematical model of a zipline, followed by experimental verification of the formed mathematical model on a particular zipline, and afterwards by an analysis of the influencing parameters. The beginning of the paper defines the theoretical background that is necessary for the mathematical model forming of descending a rider down a heavy rope that takes into account mechanical and aerodynamical resistances that occur during the descent, after which a description of formation of the model itself is given. The next part of the paper gives a detailed description of the zipline on which the measurements were made, and a complete description of the used measuring equipment. Then succeeding part contains measurement results, followed by verification of the mathematical model by comparing the measured and calculated values. In the end, the influence of relevant parameters are analyzed by using the mathematical model and adequate conclusions are drawn. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this paper is to re-visit the design of three steps in the freeze-drying process, namely freezing, primary drying, and secondary drying steps. Specifically, up-to-date recommendations for selecting freeze-drying conditions are provided based on the physical–chemical properties of formulations and engineering considerations. Methods and Results: This paper discusses the fundamental factors to consider when selecting freezing, primary drying, and secondary drying conditions, and offers mathematical models for predicting the duration of each segment and product temperature during primary drying. Three simple heat/mass transfer primary drying (PD) models were tested, and their ability to predict product temperature and sublimation time showed good agreement. The PD models were validated based on the experimental data and utilized to tabulate the primary drying conditions for common pharmaceutical formulations, including amorphous and partially crystalline products. Examples of calculated drying cycles, including all steps, for typical amorphous and crystalline formulations are provided. Conclusions: The authors revisited advice from a seminal paper by Tang and Pikal (Pharm Res. 21(2):191-200, 2004) on selecting freeze-drying process conditions and found that the majority of recommendations are still applicable today. There have been a number of advancements, including methods to promote ice nucleation and computer modeling for all steps of freeze-drying process. The authors created a database for primary drying and provided examples of complete freeze-drying cycles design. The paper may supplement the knowledge of scientists and formulators and serve as a user-friendly tool for quickly estimating the design space. [ABSTRACT FROM AUTHOR]

The assessment of scientific articles regarding their relevance to a research portfolio is becoming increasingly important. The reason is that scientific works have been growing quantitative and qualitatively. Taking this scenario into account, Methodi Ordinatio was proposed, and its major contribution was the 7th phase of the methodology, the InOrdinatio. It is an equation based on the main criteria for selecting a paper related to a theme: year of publication, number of citation and the impact factor (or journal metrics). However, finding the value of these three factors might not be an easy and quick task. Therefore, in order to improve the use of Methodi Ordinatio, two other tools were developed: FInder and RankIn. Thus, the first purpose of this paper is to present these two new tools. Additionally, considering that the impact factor has been a matter of disputes in the academia, the paper also proposes the use of one single indicator for the impact factor in the equation. To achieve this second purpose, a robust mathematical model was elaborated taking into consideration the other journal metrics in order to estimate the alternative impact factor to be used in InOrdinatio in case one or more papers are not indexed to any metrics. After testing with 48 statistical models and tools, the results show that this indicator is robust and trustworthy to be used. Finally, as the third as last purpose, this paper also proposes an alternative version to calculate the InOrdinatio, which can be flexible regarding the weight of its three criteria used in the equation. [ABSTRACT FROM AUTHOR]

In modern discrete functional semiconductor devices and structural elements of micro- and nanoelectronics, use is made of materials with anisotropy of electrical properties. In particular, such materials are crystalline thermoelectrics, layered graphite structures, and strained silicon. In the practical application of these semiconductors, it becomes necessary to measure their kinetic coefficients. However, the electrodynamics of these media differs from that of isotropic ones, which requires the correction of existing methods for measuring the conductivity and concentration of the majority charge carriers. The paper presents a technique for solving the Neumann problem with inhomogeneous boundary conditions for the electric field potential in a rectangular region in a relatively weak magnetic field in a linear approximation. The boundary value problem considered in the paper is encountered in the analysis of measurements of the Hall effect by probe methods. Using the perturbation theory and the Fourier method, an expression for the Hall field potential is obtained and presented in rectangular coordinates as a series of harmonic functions, which is convenient for further application. Practically important expressions for analyzing the results of Hall measurements by probe methods have been obtained for anisotropic samples with flat boundaries. Analysis of the obtained solution and computer simulation of the electric potential in anisotropic semiconductor wafers with flat boundaries are performed. An experimental verification of the obtained distributions of potentials and practical recommendations on the application of the obtained theoretical expressions are presented. [ABSTRACT FROM AUTHOR]

Since the discovery and the development of many technological instruments such as modern communication and communication technologies, digital media has served widely from the technology, and thus intersected quasi all life's domains, by providing news, information, and also discussions of quasi all subjects. In social sciences, for example, a major part of digital media sites discusses the well-being of both individuals, and societies, especially with the presence of many challenging phenomena like pandemics, wars, and financial crises. A major concern for QoL index for example resides in whether it is a uniform stable index or on the contrary a non-uniform index depending strongly and point-wisely on the time scale. This motivates the consideration of a non-uniform QoL index based on non-uniform wavelets to take into account the influence of many factors issued from political, social, environmental, economic effects according to the time scale. The model developed is tested on Saudi Arabia QoL index case. Recall that the Kingdom of Saudi Arabia has fixed many aims in its 2030-vision plan including the quality of life as a major goal. For example, the KSA worldwide NEOM project necessitates surely a supportive environment to be realized. The second purpose of our paper is also to study the impact of digital media such as social one on the QoL. Therefore, the data collected is basically issued from a set of conversations on social media platforms. To obtain a suitable time series, we developed a backward-forward non-uniform wavelet forecasting model to extend the data sample suitably. The whole time series is by the next applied for the QoL index dynamics and interpretations. The findings showed that effectively, the QoL index is never a stable single index on the whole year, but on the contrary, the dependence on the time scale is non-uniform. Moreover, to interpret suitably and for a correct policy, the non-uniform behavior should be considered adequately. [ABSTRACT FROM AUTHOR]

Despite artificial intelligence (AI) technology progresses at unprecedented rate, our ability to translate these advancements into clinical value and adoption at the bedside remains comparatively limited. This paper reviews the current use of implementation outcomes in randomized controlled trials evaluating AI-based clinical decision support and found limited adoption. To advance trust and clinical adoption of AI, there is a need to bridge the gap between traditional quantitative metrics and implementation outcomes to better grasp the reasons behind the success or failure of AI systems and improve their translation into clinical value. [ABSTRACT FROM AUTHOR]

The aerospace industry is pivotal for global transportation and is a cornerstone of high-tech industry growth in both developed and developing nations. Ensuring the integrity of aircraft products and components, maintenance, repair, and overhaul (MRO) operations is critical to the sector's success. This paper presents a linear programming model for scheduling aircraft C-check and D-check maintenance operations with multiple component treatment options: replacement, repair, and remanufacturing. Risk of component failure before the next maintenance is integrated into the model. The objective is to minimize maintenance cost while adhering to safety standards. The model also incorporates allocation of maintenance resources including labor and machinery capacities. Scenario analyses are conducted to assess varying parameters such as resource availability, unplanned maintenance costs, and penalty on the model solutions. The potential for remanufacturing to reduce maintenance expenses in MRO operations is evaluated. The main contribution of this work lies in its novel approach to integrating risk assessment with resource optimization in MRO scheduling with remanufacturing and in providing a comprehensive framework to enhance decision-making for MRO maintenance operations. [ABSTRACT FROM AUTHOR]

The penetration coefficient can represent the relationship between force and depth in the rock drilling process, but its understanding is limited. Therefore, based on the rock drilling theory with a hydraulic breaking hammer, a mathematical model of the penetration coefficient is established in this paper, and the main influencing factors of the penetration coefficient are determined. The discrete element method is used to establish a rock simulation model that can represent the real characteristics, and the variation law of the penetration coefficient under cyclic impact is studied. In addition, the drilling processes of drill bits with different impact velocities, shapes, and angles are simulated to evaluate the effects of operational parameters on the penetration coefficient. The results show that cyclic impact will change the rock cohesion and affect the change in the penetration coefficient. With an increase in impact times by the same drill bit, the penetration coefficient first increases and tends to be stable, and then decreases. Regarding operational parameters, the impact velocity has little effect on the penetration coefficient, while the shape and angle of the drill bit have a significant effect on the penetration coefficient, and a drill bit with a smaller angle is accompanied by more rock debris. Highlights: A theoretical model of the penetration coefficient is established. DEM simulation reveals the rock drilling mechanism under cyclic impact. The effect law and significance of operation parameters are obtained. [ABSTRACT FROM AUTHOR]

In the traditional tobacco drying process, there is often a problem of uneven drying, which is closely related to drying conditions such as air velocity and temperature. To better understand the drying characteristics of tobacco, its drying kinetic performance were experimentally studied and predicted in this paper. In the drying experiment, the range of air temperature and velocity is 20–60℃ and 0.95–4.93 m/s, respectively. The results show that the effective diffusion coefficient increases with the increase of air temperature and decreases with the increase of air velocity. The effective moisture diffusivity( D eff ) ranges from 2.077 × 10–7 to 9.136 × 10–7 m2/s. Additionally, the activation energy (Ea) is between 14.292 and 21.032 kJ/mol according to Arrhenius law. Among the six commonly used empirical correlations, the logarithmic model has higher prediction accuracy, but it has a prediction deviation of more than 20% in the later stage of drying. Based on the logarithmic model and the two models, a new prediction model of tobacco drying characteristics was proposed with a maximum relative deviation error of less than 1%. [ABSTRACT FROM AUTHOR]

Hybrid ion exchange (IX) and biological processes have been developed for various water and wastewater treatment applications. These hybrid systems integrate multiple physical, chemical, biological, hydrodynamics, and substrate transport processes to improve the treatment efficiencies and system stability. The mathematical description of the individual process has been well established previously; however, there is a lack of a holistic review and guidelines to develop hybrid models for different treatment systems. In this paper, we summarize the applications of hybrid IX and biological systems, critically review the representative individual process models, and propose the framework to integrate these models for the hybrid process. Additionally, we provide a comprehensive review of the equilibrium, kinetic, and thermodynamic models for the IX process and the key biological process models, along with their applied scenarios. Advanced data-driven modelling and its combination with mechanistic models are also discussed to overcome the drawbacks in conventional modeling approach. We highlight emerging techniques that would lead to higher fidelity models. This review provides a comprehensive guideline for the model development of hybrid systems and presents future research directions to build robust systems. [ABSTRACT FROM AUTHOR]

In this paper, the structural vibration control of short-period systems by a sliding model of a tuned liquid column damper (herein referred to as STLCD) is investigated from both theoretical and experimental points of view. The proposed STLCD is essentially composed of a U-tube container with liquid inside, which can slide on a linear guide rail and is connected to the structure by a spring-dashpot system. Unlike traditional fixed TLCDs, this type of arrangement allows the proposed STLCD to be tuned to short-period structural systems since the spring can be used for tuning while the dashpot provides additional damping. Details on the selection of the optimal design parameters of the STLCD are provided, and the validity of the introduced mathematical model is verified both in time and frequency domains through experimental tests conducted at the Laboratory of Experimental Dynamics at the University of Palermo, Italy. For the experimental tests, a scale model of an STLCD-controlled structure is considered, focusing on the reduction of the roof accelerations. Finally, for comparison purposes, the control performance of the proposed control strategy for the vibration suppression of stiff structures is evaluated by analyzing its structural responses in contrast with the corresponding uncontrolled structure under harmonic excitations. [ABSTRACT FROM AUTHOR]

Elite sports contexts are highly pressurised and frequently enforce a win-at-all-costs approach. This narrow focus on performance outcomes can potentially contribute in negative ways to the mental health of those within these environments. In this Current Opinion paper, we propose a model that outlines how key elements contributing to psychologically safe or unsafe environments may contribute to better or worse mental health outcomes, respectively. In an environment in which individuals feel safe to show their authentic selves rather than 'wear a mask', different experiences of mental health are likely to be normalised, help-seeking behaviour increased, and thus, mental health outcomes enhanced. We outline how sports teams and organisations can contribute to this through the creation of appropriate policies and procedures, in addition to leaders modelling and reinforcing positive cultural norms. It is intended that the theoretical model can inform stakeholders in elite sport as well as future research directions. [ABSTRACT FROM AUTHOR]

In this paper, we discuss the difference between the deterministic and stochastic models of nonlocal diffusion. We use a nonlocal reaction-diffusion equation and a multi-dimensional jump Markov process to analyze these mathematical models. First, we demonstrate that the difference converges to 0 in probability with a supremum norm for a sizeable network. Next, we consider the rescaled difference and show that it converges to a stochastic process in distribution on the Skorokhod space. [ABSTRACT FROM AUTHOR]

Clinical abbreviation disambiguation is a crucial task in the biomedical domain, as the accurate identification of the intended meanings or expansions of abbreviations in clinical texts is vital for medical information retrieval and analysis. Existing approaches have shown promising results, but challenges such as limited instances and ambiguous interpretations persist. In this paper, we propose an approach to address these challenges and enhance the performance of clinical abbreviation disambiguation. Our objective is to leverage the power of Large Language Models (LLMs) and employ a Generative Model (GM) to augment the dataset with contextually relevant instances, enabling more accurate disambiguation across diverse clinical contexts. We integrate the contextual understanding of LLMs, represented by BlueBERT and Transformers, with data augmentation using a Generative Model, called Biomedical Generative Pre-trained Transformer (BIOGPT), that is pretrained on an extensive corpus of biomedical literature to capture the intricacies of medical terminology and context. By providing the BIOGPT with relevant medical terms and sense information, we generate diverse instances of clinical text that accurately represent the intended meanings of abbreviations. We evaluate our approach on the widely recognized CASI dataset, carefully partitioned into training, validation, and test sets. The incorporation of data augmentation with the GM improves the model's performance, particularly for senses with limited instances, effectively addressing dataset imbalance and challenges posed by similar concepts. The results demonstrate the efficacy of our proposed method, showcasing the significance of LLMs and generative techniques in clinical abbreviation disambiguation. Our model achieves a good accuracy on the test set, outperforming previous methods. [ABSTRACT FROM AUTHOR]

Lighter-than-air (LTA) aerial vehicles such as airships and aerostats can be found in various strategic and commercial applications, primarily due to their capability to hover and stealth. The mathematical model of these vehicles helps in understanding their complex dynamics and designing and developing proper stabilisation systems for them. Stability derivatives have been used for developing mathematical models for heavier-than-air aerial vehicles since their introduction. This paper presents a methodology to develop a mathematical model of an aerostat based on stability derivatives. One of the major contributions of this study is the estimation of aerostat's added mass terms expressed as longitudinal stability derivatives due to acceleration of the longitudinal motion variables. A longitudinally decoupled linear mathematical model of a single-tethered aerostat using stability derivatives is investigated in this study. A computational fluid dynamics (CFD)-based analysis of the 3D model of the vehicle is used to obtain the stability derivatives. The methodology presented considers the aerostat and tether models separately before coupling them to create the full model. The stability derivative analysis is carried out using ANSYS Fluent, and the coupled tethered aerostat model is investigated using MATLAB 2020. The negative pitch angle of the aerostat is caused by the selection of the pitching centre as the aerostat centre of volume instead of the tether confluence point. The tension force on the tether, which is proportional to the wind velocity, and aerostat velocity components are found to be stabilised within 200–400 s. [ABSTRACT FROM AUTHOR]

Sustainability is an issue of worldwide concern. Twitter is one of the most popular social networks, which makes it particularly interesting for exploring opinions and characteristics related to issues of social preoccupation. This paper aims to gain a better understanding of the activity related to sustainability that takes place on twitter. In addition to building a mathematical model to identify account typologies (bot and human users), different behavioural patterns were detected using clustering analysis mainly in the mechanisms of posting tweets and retweets). The model took as explanatory variables, certain characteristics of the user's profile and her/his activity. A lexicon-based sentiment analysis in the period from 2006 to 2022 was also carried out in conjunction with a keyword study based on centrality metrics. We found that, in both bot and human users, messages showed mostly a positive sentiment. Bots had a higher percentage of neutral messages than human users. With respect to the used keywords certain commonalities but also slight differences between humans and bots were identified. [ABSTRACT FROM AUTHOR]

Recovering three-dimensional structure from images is one of the important researches in computer vision. The quality of feature matching is one of the keys to obtaining more accurate results. However, as different objects or different surfaces of objects have similar images with the same elements and different typography, the camera pose estimation will be wrong and the task will fail. This paper proposes a new mismatch elimination algorithm based on global topology consistency. We first formulate the matching task as a mathematical model based on the global constraints, then convert the feature matching into grid matching, calculate the confidence of the grids according to the changes in the angle and displacement between correspondence grid vectors, and remove the mismatches with low confidence. The experiments have demonstrated that our proposed method performs better than the state-of-the-art feature matching methods to accomplish outlier match rejection in the task of similar image matching and could be helped to obtain the correct camera pose to reconstruct more complete and more accurate object models. [ABSTRACT FROM AUTHOR]

The photovoltaic (PV) cell behavior is characterized by its current–voltage relationship. This relationship is dependent on the PV cell's equivalent circuit parameters. Accurate estimation of such parameters is essential to study and analyze the PV system performance in terms of many aspects such as modeling and control. The main purpose of this paper is to develop mathematical models for the parameters of the single-diode poly and monocrystalline PV cells. The models are formulated using Eureqa software by utilizing training data collected from simulating thousands of PV modules available in Simulink library. The developed models can be easily and instantly executed by only using information available from module datasheet under standard test conditions (STC). The models are then validated using four different assessments by considering testing data, commercial PV modules, and experimental data, in addition to benchmarking with other reported algorithms. As an overall evaluation, the assessments have shown that the developed models are efficient in estimating the PV cell equivalent circuit parameters and can consequently predict the I–V curves for any poly or monocrystalline PV modules, under any weather conditions, with a high degree of accuracy. [ABSTRACT FROM AUTHOR]

Mathematical models of cancer and bacterial evolution have generally stemmed from a gene-centric framework, assuming clonal evolution via acquisition of resistance-conferring mutations and selection of their corresponding subpopulations. More recently, the role of phenotypic plasticity has been recognized and models accounting for phenotypic switching between discrete cell states (e.g., epithelial and mesenchymal) have been developed. However, seldom do models incorporate both plasticity and mutationally driven resistance, particularly when the state space is continuous and resistance evolves in a continuous fashion. In this paper, we develop a framework to model plastic and mutational mechanisms of acquiring resistance in a continuous gradual fashion. We use this framework to examine ways in which cancer and bacterial populations can respond to stress and consider implications for therapeutic strategies. Although we primarily discuss our framework in the context of cancer and bacteria, it applies broadly to any system capable of evolving via plasticity and genetic evolution. [ABSTRACT FROM AUTHOR]

Discovering nonlinear differential equations that describe system dynamics from empirical data is a fundamental challenge in contemporary science. While current methods can identify such equations, they often require extensive manual hyperparameter tuning, limiting their applicability. Here, we propose a methodology to identify dynamical laws by integrating denoising techniques to smooth the signal, sparse regression to identify the relevant parameters, and bootstrap confidence intervals to quantify the uncertainty of the estimates. We evaluate our method on well-known ordinary differential equations with an ensemble of random initial conditions, time series of increasing length, and varying signal-to-noise ratios. Our algorithm consistently identifies three-dimensional systems, given moderately-sized time series and high levels of signal quality relative to background noise. By accurately discovering dynamical systems automatically, our methodology has the potential to impact the understanding of complex systems, especially in fields where data are abundant, but developing mathematical models demands considerable effort. Discovering nonlinear differential equations from empirical data is a significant challenge, often requiring manual parameter tuning. This paper introduces a machine learning method integrating denoising techniques, sparse regression, and bootstrap confidence intervals, which shows consistent accuracy in identifying 3D dynamical systems with moderate data size and high signal quality. [ABSTRACT FROM AUTHOR]

A non-linear mathematical model of underactuated airship is derived in this paper based on Euler-Newton approach. The model is linearized with small disturbance theory, producing a linear time varying (LTV) model. The LTV model is verified by comparing its output response with the result of the nonlinear model for a given input signal. The verified LTV model is used in designing the LQT controller. The controller is designed to minimize the error between the output and required states response with acceptable control signals using a weighted cost function. Two LQT controllers are presented in this work based on two different costates transformations used in solving the differential Riccati equation (DRE). The first proposed assumption of costates transformation has a good tracking performance, but it is sensitive to the change of trajectory profile, whereas the second one overcomes this problem due to considering the trajectory dynamics. Therefore, the first assumption is performed across the whole trajectory tracking except for parts of trajectory profile changes where the second assumption is applied. The hybrid LQT controller is used and tested on circular, helical, and bowed trajectories. The simulation assured that the introduced hybrid controller results in improving airship performance. [ABSTRACT FROM AUTHOR]

This study examines Einstein's field equations in the context of general relativity, comparing five distinct methodologies: (a) vanishing complexity, (b) embedding class one or the Karmarkar condition, (c) conformally flat spacetime, (d) conformal killing symmetry, and (e) the Karmarkar scalar condition. The first four methods reveal a significant connection between two metric potentials, while the fifth method provides a coordinate-independent condition expressed in terms of structural scalars. The paper provides a comprehensive comparative analysis of a new exact solution derived by assuming a common metric function and solving the remaining metric functions through corresponding bridge equations to evaluate their effectiveness and validity. Critical parameters such as thermodynamic factors, causality conditions, stability, and mass function analysis are investigated. [ABSTRACT FROM AUTHOR]

The development of nanotechnology and nanoscience is largely dependent upon nanopatterning and nanofabrication and it is commonly achieved by photolithography which has been evolved is last decade so that 90 nm and even 65 nm line-width can be achieved in the semiconductor industry i.e. digital manufacturing sector in recent times. Laser-assisted nanoimprint lithography is a process in which polymer is melted by a single excimer laser pulse followed by imprinted by a mould made of fused quartz. Present research work is focused on silicon materials and utilized a single KrF excimer laser pulse (248 nm wavelength and 30 ns pulse duration) as the heating source. Mathematical modelling is carried out on the basis of hybrid application of Duhamel's application and finite integral transform approach. The thermal field is investigated in both mould and substrate surface for different nanoscale process parameters. For the first time, most updated heat transfer model is employed in this arena as dual-phase-lag heat conduction model is universally accepted for application in microscale and nanoscale structures. The research outcome is successfully validated with the published research papers and the importance of multi-dimensional modelling in the arena of nanofabrication has been demonstrated. [ABSTRACT FROM AUTHOR]

The aim of this paper is to propose a qualitative approach to the theory of conceptual spaces, in contrast to the usual metric framework. This requires qualitative notions of similarity, simple concepts, prototypes and conceptual categorisation. For this purpose, I will introduce three mathematical models for conceptual spaces. The first one is topological and has been proposed by Mormann. The other two are new and are based on atomistic orders and similarity relations. I will discuss how each of them deals with the Design Principles proposed by Douven and Gärdenfors and with further Adequacy Conditions. Despite being apparently different, I will show that these three models are mathematically equivalent. Finally, I will address three objections to the present approach. The first one says that the qualitative notion of a prototype is a bad analogue of the metric one. The second one suggests that, in contrast to the Voronoi construction, the function qualitatively representing the conceptual categorisation process is arbitrary. The last one appeals to Goodman's companionship and imperfect community problems to show that there is a flaw in defining simple concepts from similarity relations. [ABSTRACT FROM AUTHOR]

In recent years, path dependence has gained increasing scientific attention in many disciplines, leading to various new concepts and notations, such as path creation or path plasticity. However, if mathematical arguments are used, they are based on the early works by Brian W. Arthur and Paul A. David, usually referring to the mathematical concept of ergodicity. We extend their mathematical framework and develop a graphical representation of systems that allows for a metaphorical discussion of system behaviors beyond the original cases, especially in evolving systems, and the inclusion of the recently developed concepts within path dependence. Visualizations are used to explain the definition and characteristics of seven types of path dependence: lock-in, path-breaking, path-furrowing, path plasticity, path formation, path creation, and path selection. Although these visualizations are explained verbally and can be understood without a mathematical expertise, a mathematical model is used to generate them. The deduction of the metaphorical concept from a mathematical model guarantees the completeness of the identified processes and the rigor in their categorization as well as the identification of respective characteristics for their distinction. However, the aim of the paper is to provide an illustrative concept that allows researchers to classify and structure the various path-dependent processes they observe in their application. While five of the identified processes are in line with concepts from the literature and are defined accordingly, we also detect a sixth process that is new to the literature so far: path-furrowing. Moreover, slightly deviating from the literature, we define path selection as the possibility to choose a path intentionally, thereby focusing on the mindful choice of options. [ABSTRACT FROM AUTHOR]

The paper introduces a mathematical model based on the discrete element method, presenting the results of its application to simulate the movement of briquetted mass within the working chamber of the extruder. This model accounts for the adhesive interaction among particles within the mixture. The simulation results provide a qualitative and quantitative description of the displacement and compaction of the briquetted mass. They allow the flow structure to be visualized and the distribution of velocities and the moment on the screw axis during the extrusion process to be determined. Furthermore, a digital twin of the pug sealer–extruder unit was created through finite element modeling. The results obtained from this digital twin can be used to optimize the operational parameters of extrusion briquette equipment. In addition, by using the developed model, the process of mixing binder materials with a briquetted mixture at various volumes of the added binder was studied. [ABSTRACT FROM AUTHOR]

The paper proposes a methodology for mathematical modeling of the phased development of nodes and transport routes in a hierarchical network with multicommodity discrete flows of correspondences based on solving the problems of optimizing its structure and distribution of flows. As a rule, such networks consist of a decentralized mainline network and networks in the internal service areas of mainline nodes. In a multicommodity network, each node can exchange correspondence (products, goods, cargo, messages) with the other nodes. Correspondence is characterized by a source node, a sink node, and a quantity, which for data transmission networks is given by the number of bytes, kilobytes, etc., and for transport networks by the number of cargo units in a package of uniform size. In the mainline network, all correspondences are transmitted via communication channels or transported by vehicles in transport units of a given size (capacity, volume). The authors considered the main postulates of generating a mathematical model of the perspective development of mainline network. They presented a method of mathematical modeling of the phased development of nodes and transport routes, which includes, for each stage of development, the forecasting of data and network parameters, solving the problem of packing correspondence and choosing the structure of the network, and solving the problem of distribution and routing of transport unit flows. [ABSTRACT FROM AUTHOR]

The paper considers the problem of variational assimilation of observational data in order to reconstruct the initial state and heat fluxes for the mathematical model of sea thermodynamics developed at the Marchuk Institute of Numerical Mathematics, Russian Academy of Sciences. The sensitivity of the functionals of the solution to the input data on the heat flux on the sea surface in the considered variational assimilation problem is studied, and the results of numerical experiments for the Black Sea dynamics model are presented. [ABSTRACT FROM AUTHOR]

The therapeutic alliance has a robust association with positive outcome in psychotherapy. It is considered a common factor of change independent of the diagnosis and type of therapy. The alliance is commonly defined phenomenologically as a relationship between a client and a therapist characterized by such attributes as agreement on the goals of the treatment, agreement on the tasks, and a personal bond made up of reciprocal positive feelings. There is no commonly accepted mechanistic model of the alliance. In this paper, we present the alliance in active inference terms as an affiliative behavioral strategy meant to decrease the free energy of the participants' generative models of each other and of their social exchange. In this view, the initial apprehension of affiliation with a stranger is a normative reaction in the therapeutic (or any social) encounter. We identify trust and self-efficacy as processes central to the development of the alliance and suggest an active inference model of the alliance based on their interaction and dynamics. The paper concludes with suggestions for the model's practical application. [ABSTRACT FROM AUTHOR]

Purpose : People experiencing intimate partner violence (IPV) often seek, or are referred to, specialized service providers such as shelter workers, counsellors in programs for children exposed to IPV, and facilitators for men's behaviour change programs. This paper discusses the process of collaborating with service providers and survivors across Canada to articulate the often-unrecognized knowledge and skills of IPV specialists. Methods: Work included a scoping review and analysis of 140 academic and practice papers, interviews with 62 expert service providers, eight Delphi-method surveys and over 70 hours of collaborative discussion with expert working groups of experienced service providers and survivors. Results: Areas of knowledge and skill were drafted based on the review of literature and analysis of interviews with experienced service providers, then rated in Delphi surveys, and discussed by expert working groups. Consensus was reached on the Flourishing Practice Model which identifies nine areas of capability shared across IPV specialists, as well as unique knowledge and skills used to support and collaborate with survivors, recognize and respond to infant, child and youth experiences of violence and intervene to end abusive behaviours. The "stem" recognizes the critical role of IPV specialist organizations and leaders in supporting service providers' capabilities. "Blank petals" are included to signify expertise that has not yet been documented and to recognize ongoing growth. Conclusions: The combination of methods and processes allowed for the integration of research and practice knowledge with survivor and service provider voices to gain deeper insight into the knowledge and skills of IPV specialists. [ABSTRACT FROM AUTHOR]

This paper proposes a method to deform a continuum robot into a complex shape with distributed curvature using a single motor drive. This continuum robot can be deformed to a desired shape by placing tendon guides at appropriate intervals. We used several target shapes, including clothoid and sin curves, as well as a circular curve of constant curvature and confirmed that the deformed shapes match them both in the simulation and prototype. This paper proposes two models of continuum robots. One is the Plain Model in which the tendons are parallel to the rod and the Penetration Model in which the tendon penetrates to the rod. By placing the penetrating position(s), this continuum robot can be deformed into a shape with inflection point(s). We designed a mathematical model to simulate the deformed shape of the prototype to obtain the proper placement of the guides and penetration point(s). Through the optimization, it was able to find the parameters that, in most cases, result in the error of less than 4 % between the target and deformed shapes on simulation. We applied these conditions to the prototype and evaluated the errors, which were approximately 10 % , the same as the related works that use a conventional constant curvature model. We think that the results of this paper can be applied to reduce the number of actuators required and the size and weight of continuum or biomimetic robots. [ABSTRACT FROM AUTHOR]

This paper proposes a method to deform a continuum robot into a complex shape with distributed curvature using a single motor drive. This continuum robot can be deformed to a desired shape by placing tendon guides at appropriate intervals. We used several target shapes, including clothoid and sin curves, as well as a circular curve of constant curvature and confirmed that the deformed shapes match them both in the simulation and prototype. This paper proposes two models of continuum robots. One is the Plain Model in which the tendons are parallel to the rod and the Penetration Model in which the tendon penetrates to the rod. By placing the penetrating position(s), this continuum robot can be deformed into a shape with inflection point(s). We designed a mathematical model to simulate the deformed shape of the prototype to obtain the proper placement of the guides and penetration point(s). Through the optimization, it was able to find the parameters that, in most cases, result in the error of less than 4 % between the target and deformed shapes on simulation. We applied these conditions to the prototype and evaluated the errors, which were approximately 10 % , the same as the related works that use a conventional constant curvature model. We think that the results of this paper can be applied to reduce the number of actuators required and the size and weight of continuum or biomimetic robots. [ABSTRACT FROM AUTHOR]

In this paper, a method has been developed for heat treatment of details with a complex surface profile with a rapidly oscillating laser beam with modulated radiation power. This method is an alternative method for the dynamic formation of the distribution of the intensity of the laser spot. A mathematical model for calculating the distribution of the intensity of the oscillating beam and temperature fields induced by laser treatment is created. An algorithm for optimizing the parameters of high-frequency oscillations of the beam based on the solution of the inverse problem of thermal conductivity to obtain uniform heating of the near-surface layer of the material is developed. [ABSTRACT FROM AUTHOR]