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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]

In museums, libraries and archives, some of the paper relics, upon ageing, are very brittle and even cannot be handled without destroying the material. This is because of the depolymerization of cellulose and, consequently, the loss of mechanical strength. To prolong the life expectancy of paper relics, the poly(methyl methacrylate- co-butyl acrylate- co-styrene) (MMA-BA-ST) was used to strengthen the fragile paper fibers in this work. The relation between the mass concentration of MMA-BA-ST emulsion and the specific properties of papers (e.g., folding endurance, tensile strength, tearing strength, whiteness and glossiness) and the ageing resistance were investigated. In addition, the effect of MMA-BA-ST on different types of paper was also studied. Furthermore, the reinforcing mechanism of MMA-BA-ST on paper was also investigated by dissipative particle dynamics simulations. The results showed that MMA-BA-ST could significantly improve the mechanical properties and ageing resistance of papers. [ABSTRACT FROM AUTHOR]

This paper presents a brief overview of the use of magnetic field in studying droplet adhesion to a fiber or a fibrous surface. The paper starts by discussing ways to quantify the force required to detach a droplet from a fiber for its applications in coalescence filtration, i.e., removal of dispersed droplets from a gaseous or liquid flow using a fibrous filter. It then continues to discuss droplet detachment from a fibrous surface or penetrating into a thin fibrous coating. The emphasis is put on a recently develop magnetic approach for measuring force of detachment and on its novel simplicity and non-intrusive nature in the context of existing droplet detachment methods. Our review also includes a discussion on force of detachment for multiphase droplets comprised of two immiscible liquids, i.e., compound droplets. Atomistic- and continuum-level numerical simulations pertaining to droplet detachment are also discussed throughout the paper when appropriate. [ABSTRACT FROM AUTHOR]

Nano-modification is one of the effective methods to improve insulation characteristic of dielectric materials. In this paper, SiO2-modified oil-impregnated paper (OIP) is prepared to study space charge accumulation and trap level characteristic, and a bipolar charge transport model adding double trap level is established to simulate space charge accumulation. Space charge density and distribution range of SiO2-modified OIP are less than those of pure OIP, and 2.4 wt% and 3.8 wt% SiO2-modified OIP have space charge suppression. Moreover, surface charge decay rate and amplitude of SiO2-modified OIP are less than non-modified OIP, and those of 2.4 wt% SiO2-modified OIP are least. The trap level distribution is calculated according to the ISPD results, indicating that SiO2-modification decreases the shallow trap density, and increases the deep trap density and the trap level. The effect of SiO2-modification on deep trap level is larger than that on the shallow trap. The simulation results indicate that the charge transport model can simulate and explain the mechanism of space charge accumulation in SiO2-modified OIP. [ABSTRACT FROM AUTHOR]

Loop-mediated isothermal amplification or LAMP has been identified to be an efficient technology for point-of-care diagnostics. Paper-based LAMP technique has tremendous potential in replacing the existing tube-based technology as the manufacturing cost of a paper-based device is comparatively lower and easy-to-use. LAMP-based paper diagnostic device for Mycobacterium tuberculosis (MTB) detection is of extreme importance as it will help in early and rapid diagnosis of the affected patients. The fabrication of these devices requires assessment of design parameters on the extent of LAMP amplification reaction. Hence, CFD studies would be extremely beneficial from the design perspective. The current work presents an insight into the CFD simulations for LAMP amplification reaction on a porous paper membrane (nitrocellulose membrane). The convection-diffusion-reaction model is solved on a COMSOL Multiphysics 5.0 platform. Studies on effect of pore size, aspect ratio and initial DNA concentration on the extent of DNA amplification reaction have been carried out. The current paper-based technique is effective in detecting a minimum of 5 copies of DNA contrasting the previous semi-quantitative technique which demonstrated the detection of minimum 98 copies. Overall, the simulation results displayed almost 96% enhancement in the DNA amplification rate on paper membrane. Graphical abstract Graphical abstract for the computational study of DNA amplification reaction via LAMP technique on a porous paper membrane. [ABSTRACT FROM AUTHOR]

Deep water areas with soft subsea soils, conventional surface conductor into the mud depth is too deep, long waiting time for resting, prone to surface conductor sinking and submerged wellhead instability. In this paper, based on the basic principles of mechanics and the understanding of the structure of the surface conductor, a mechanical model of the bearing capacity of the surface conductor is established. Three types of expandable surface conductors were designed by changing the distribution of the expansion material, in contrast to conventional surface conductors. The bearing characteristics of different structural surface conductors are also investigated by changing the soil parameters from the strength of the submarine soil. The study has obtained: the load-bearing capacity comparison graph between conventional surface conductor and expandable surface conductor; the load-bearing capacity change of expandable surface conductor under the change of soil parameters and the change of expansion material section; and the load-bearing capacity improvement effect of the three expandable surface conductors designed in the paper compared with conventional surface conductors, using stress as the evaluation criterion. This paper provides technical support for the design of expandable surface conductors and provides a basis for numerical simulation of surface well construction. [ABSTRACT FROM AUTHOR]

The influence of the sealing degree of the lining structure and the permeability of surrounding rock on the stability of the tunnel has always been the main topic concerned by the relevant engineering researchers. Based on the research background of the tunnel project of Qingdao metro line 1 and the in-depth analysis of the existing research results, this paper makes a systematic analysis and research on the influence mechanism of the sealing degree of the lining structure and the permeability of surrounding rock on the stability of the tunnel by the numerical simulation. The results show that the safety coefficient of each part of lining structure decreases with the increasing degree of tunnel sealing, which is manifested by the increase of the settlement of the vault and the convergence of the arch foot. In addition, the stability of surrounding rock becomes worse with the increase of permeability coefficient of surrounding rock, which means the higher pore pressure and larger displacement of rock around the chamber. At the same time, the influence of the sealing degree of the lining structure on the stability of the tunnel will increase with the permeability of the surrounding rock. The works in this paper have guiding significance for the construction of submarine tunnel under different characteristics of surrounding rock and the selection of sealing degree of lining structure. [ABSTRACT FROM AUTHOR]

This paper considers theoretical foundations and mathematical methods of data analysis under the conditions of the Rice statistical distribution. The problem involves joint estimation of the signal and noise parameters. It is shown that this estimation requires the solution of a complex system of essentially nonlinear equations with two unknown variables, which implies significant computational costs. This study is aimed at mathematical optimization of computer algebra methods for numerical solution of the problem of Rician data analysis. As a result of the optimization, the solution of the system of two nonlinear equations is reduced to the solution of one equation with one unknown variable, which significantly simplifies algorithms for the numerical solution of the problem, reduces the amount of necessary computational resources, and enables the use of advanced methods for parameter estimation in information systems with priority of real-time operation. Results of numerical experiments carried out using Wolfram Mathematica confirm the effectiveness of the developed methods for two-parameter analysis of Rician data. The data analysis methods considered in this paper are useful for solving many scientific and applied problems that involve analysis of data described by the Rice statistical model. [ABSTRACT FROM AUTHOR]

In this paper, the impact of varying path loss exponent (PLE) on user association probability, decoupled uplink coverage probability as well as decoupled uplink average spectral efficiency in downlink uplink decoupled (DUDe) multi-tier heterogeneous networks, is investigated. We investigate the effect of the difference in path loss exponents in both macro and small cell environments over uplink network performance. It is assumed that the mobile user connected to the macro base station experience different path loss exponent as compared to when connected to small base station. It is observed that the difference of path loss exponents in both cases has significant effect on the user association probability, decoupled uplink coverage probability as well as decoupled uplink average spectral efficiency. Moreover, in order to further support key findings and make sound comparison between coupled and DUDe performance in varying PLE environment, generalized analytical expressions for coupled association probabilities, along with coupled uplink coverage probability and coupled uplink average spectral efficiency have been derived. The analytical results evaluated in this paper are compared with the computer simulation and found in good agreement. Our analysis shows that decoupling technique performs suboptimal for cases where the environments around macro and small base stations are different with respect to each other. The work explained in this paper highlights the limitation of applying DUDe technique in realistic conditions where the PLEs of cellular tiers are not exactly equal to one another. [ABSTRACT FROM AUTHOR]

Land subsidence has become a widespread engineering geological problem, which can quickly induce many derived disasters. Over-exploitation of groundwater is one of the main factors of urban land subsidence. There is severe land subsidence in Jining, mainly induced by groundwater over-extraction. Therefore, the numerical simulation method is used in this paper to analyze and predict the law of land subsidence in Jining. Combined with the engineering geological and hydrogeological conditions of Jining City, a three-dimensional fluid–solid coupling model of land subsidence was established by using COMSOL software. The numerical results were verified using site monitoring data. The article predicts the land subsidence in the study area in 2030. In 2030, the maximum land subsidence is 224 mm. And this paper analyzes the land subsidence pattern under different groundwater extraction amounts. The results show that the land subsidence in the study area is effectively alleviated under the condition of reducing water extraction by 30%. It provides a basis for preventing and controlling land subsidence in Jining city. It is proved that land subsidence caused by groundwater extraction positively correlates with the pumping time and amount of water pumped. [ABSTRACT FROM AUTHOR]

The spectrum sharing paradigm is a promising countermeasure to the spectrum under-utilization problem. However, it causes both primary interference (inflicted by primary transmitters upon secondary receivers) and secondary interference (inflicted by secondary transmitters upon primary receivers) and un-secures information transmission. Most works ignored the primary interference and considered the Rayleigh fading in evaluating the information security of the spectrum sharing paradigm. This paper generalizes these works with considerations of the primary interference and the Nakagami-m fading. First, the exact expression of the secrecy outage probability is proposed for the spectrum sharing paradigm under considerations of both primary/secondary interferences, the Nakagami-m fading, and the peak transmit and interference power constraints. Then, computer simulations are provided to corroborate the proposed expression. Finally, numerous simulation/theory results are generated to assess the security performance in key system parameters such as the fading severity degree, the primary interference level, the peak transmit power, the peak interference power, the security threshold. [ABSTRACT FROM AUTHOR]

This paper approaches the problem of testimony from a new direction. Rather than focusing on the epistemic grounds for testimony, it considers the problem from the perspective of an individual who must choose whom to trust from a population of many would-be testifiers. A computer simulation is presented which illustrates that in many plausible situations, those who trust without attempting to judge the reliability of testifiers outperform those who attempt to seek out the more reliable members of the community. In so doing, it presents a novel defense for the credulist position that argues one should trust testimony without considering the underlying reliability of the testifier. [ABSTRACT FROM AUTHOR]

In order to enhance the stability of the tilt transition process, a new configuration of Quad-Tiltrotor UAV was presented in this paper. Firstly, numerical simulation was used to calculate and analyze the aerodynamic interaction between the front rotor/fuselage/rear rotor during the transition state mode. The calculation model of the isolated rotor, front-rear rotor, front rotor-fuselage, and front rotor-rear rotor-fuselage combination states are established. Besides, the effects of pitch, roll, and yaw moment on the fuselage at different tilt angles are analyzed. It is concluded that the front rotor is the leading factor in the aerodynamic interference of the whole UAV in the different combination states. The research results can provide a reference for the optimization design of the overall layout, structure, and flight control strategy of the cross-shaped quad-tiltrotor UAV, and can also provide solutions for the logistics application of urban air traffic. [ABSTRACT FROM AUTHOR]

Explosively formed projectile (EFP) has the advantages of high flight speed, high burst height, insensitivity to initial velocity, etc. To study the forming performance of multiple explosively formed projectile (MEFP) and to analyze the factors influencing the forming results. A directional pentagonal prism MEFP with five liners is proposed in this paper. Experiments were conducted to validate the performance of this MEFP. The experimental results show that the generated EFPs have high flight speeds. However, the EFP hit position on the target plate was offset, causing multiple positional penetrations. To analyze the causes of the phenomenon, a numerical simulation model of directional MEFP is established and the forming process of MEFP is numerically simulated. The simulation results indicate that the EFP fracture occurs during the forming process due to the asymmetric detonation wave, and its tail cannot be fully closed. Combined with the numerical simulation and experimental results, the forming performance of the liners used in the MEFP has been further developed. Further analysis was carried out on the effect of liner thickness and height on forming performance. It can be seen that as the thickness of the liners increases, the length of the head of EFP increase, the incidence of EFP tail fracture decreased, the aspect ratio increases and the EFP velocity decrease. As the height of the MEFP increases, the velocity of the EFP increases, the head ratio increases, the shape of the detonation wave tends to be symmetrical, and the tendency of the EFP to appear as an unclosed tail decreases. [ABSTRACT FROM AUTHOR]

The present paper shows the development of a strategy for the calculation of the air brake forces of European freight trains. The model is built to upgrade the existing Politecnico di Torino longitudinal train dynamics (LTD) code LTDPoliTo, which was originally unable to account for air brake forces. The proposed model uses an empirical exponential function to calculate the air brake forces during the simulation, while the maximum normal force on the brake friction elements is calculated according to the indication of the vehicle braked weight percentage. Hence, the model does not require to simulate in detail the fluid dynamics in the brake pipe nor to precisely know the main parameters of the braking system mounted on each vehicle. The model parameters are tuned to minimize the difference between the braking distance computed by the LTDPoliTo code and the value prescribed by the UIC 544-1 leaflet in emergency braking operations. Simulations are run for different configurations of freight train compositions including a variable number of Shimmns wagons trailed by an E402B locomotive at the head of the train, as suggested in a reference literature paper. The results of the proposed method are in good agreement with the target braking distances calculated according to the international rules. [ABSTRACT FROM AUTHOR]

We present an interactive system that allows users to design original pop-up cards. A pop-up card is an interesting form of papercraft consisting of folded paper that forms a three-dimensional structure when opened. However, it is very difficult for the average person to design pop-up cards from scratch because it is necessary to understand the mechanism and determine the positions of objects so that pop-up parts do not collide with each other or protrude from the card. In the proposed system, the user interactively sets and edits primitives that are predefined in the system. The system simulates folding and opening of the pop-up card using a mass-spring model that can simply simulate the physical movement of the card. This simulation detects collisions and protrusions and illustrates the movement of the pop-up card. The results of the present study reveal that the user can design a wide range of pop-up cards using the proposed system. [ABSTRACT FROM AUTHOR]

This paper devises a neural-network-based data-driven (NN-DD) algorithm to address the trajectory tracking control (TC) of discrete non-affine MIMO systems with unknown models and repetitive operation patterns. Data-driven control no longer relies on the precise model of the controlled system, thereby breaking free from the limitations of model-based control strategies. Inspired by this, the primary objective of the algorithm is to ensure that the tracking error of the system is uniformly ultimately bounded through a data-driven approach. The algorithm is comprised of a DD modeling approach based on an enhanced stochastic configuration network (ESCN), and a control input solving approach based on radial basis function neural networks (RBFNNs). The numerical simulations indicate that the proposed algorithm achieves a decrease in the modeling error to 3.29 e - 7 and the tracking error to 1 e - 8 after just 20 iterations. In addition, the numerical simulations also demonstrate that the modeling algorithm based on an ESCN reduces the modeling errors by 48.11 % and 99.95 % respectively compared to the modeling algorithms using only stochastic configuration networks (SCNs) or extreme learning machines (ELMs). Regarding tracking errors, the proposed RBFNN-based controller reduces the tracking error by 100 % compared to the backpropagation NN (BPNN)-based controller. Furthermore, the robustness of the algorithm against time-varying interference is tested via the unmanned vehicle simulations. This paper covers several contributions: 1) The proposed algorithm is entirely DD and can directly establish the relationship between inputs and outputs. 2) The designed ESCN fully integrates the advantages of SCNs and ELMs, in contrast to simply combining basic algorithms. 3) The RBFNN-based controller is independent of the actual system structure and exhibits excellent generalization capabilities. [ABSTRACT FROM AUTHOR]

Change in groundwater dynamics (in terms of changes in depth to watertable and its salinity) is a key environmental concern for agricultural production using pulp and paper mill effluent for irrigation purposes. At the study site, the treated effluent is delivered from the mill into a winter storage dam. This storage dam is also meant to provide an opportunity for runoff collection and recycling for irrigated areas. A natural creek also exists along the farm boundary. This paper presents, using field observation data and computer simulation results, the impact of using treated effluent from the pulp and paper mill on groundwater dynamics at the farm (covering areas both under and outside the effluent irrigation paddocks); and on the flows in the adjacent creek. The modeling results show that after 5 years of operations, the change in aquifer storage is more under average climatic conditions (−23.5 mm/year) as compared to −7.1 and −9.0 mm/year under dry and wet climatic conditions, .respectively. Under average climatic conditions, the combined effect of irrigation and rainfall creates more hydraulic gradient towards the creek thereby depleting the aquifer storage more as compared to wet and dry climatic conditions. Resultantly, the subsurface groundwater flows towards the creek becomes around 57.9 mm/year under average scenario as compared to 55.0 and 36.7 mm/year under wet and dry climatic conditions, respectively. During the average climatic condition, 456.6 mm evaporation from shallow groundwater was estimated under the current management practices; which was reduced to 399.1 mm under the best management practices due to better use of all sources of water and capillary upflow from shallow groundwater. Thus, with the adoption of best management practices, there would be less risk of salinisation due to evaporation from shallow groundwater tables. [ABSTRACT FROM AUTHOR]

Publication has long been believed as the most accepted and reliable way of presenting key findings of a research. A growing demand, on the other hand, is seen on the research in different aspects of the engineering discipline raising the concern that whether researchers can have specialized skills to produce quality papers in engineering. This paper aims at studying key features affecting publications at large, with the tendency towards engineering science. Basic considerations from defining the topics up until drafting manuscripts and eventually submission as well as treatment of papers after submission is considered so as to achieve quality publications in engineering. [ABSTRACT FROM AUTHOR]

Purpose: To look at the bibliometric publication trends on 'Urolithiasis' and aspects of treatment and training associated with it over a period of 16 years from 2000 to 2015. To this end, we conducted this study to look at the publication trends associated with urolithiasis, including the use of simulation, laser technology, and all types of interventions for it. Materials and methods: We performed a systematic review of the literature using PubMed over the last 16 years, from January 2000 to December 2015 for all published papers on 'Urolithiasis'. While there were no language restrictions, English language articles and all non-English language papers with published English abstracts were also included. Case reports, animal and laboratory studies, and those studies that did not have a published abstract were excluded from our analysis. We also analyzed the data in two time periods, period-1 (2000-2007) and period-2 (2008-2015). Results: During the last 16 years, a total of 5343 papers were published on 'Urolithiasis', including 4787 in English language and 556 in non-English language. This included papers on URS ( n = 1200), PCNL ( n = 1715), SWL ( n = 887), open stone surgery ( n = 87), laparoscopic stone surgery ( n = 209), pyelolithotomy ( n = 35), simulation in Endourology ( n = 82), and use of laser for stone surgery ( n = 406). When comparing the two time periods, during period 2, the change was +171% ( p = 0.007), +279% ( p < 0.001), and −17% ( p = 0.2) for URS, PCNL, and SWL, respectively. While there was a rise in laparoscopic surgery (+116%), it decreased for open stone surgery (−11%) and pyelolithotomy (−47%). A total of 82 papers have been published on simulation for stone surgery including 48 papers for URS (67% rise in period-2, p = 0.007), and 34 papers for PCNL (480% rise in period-2, p < 0.001). A rising trend for the use of laser was also seen in period 2 (increase of 126%, p < 0.02, from 124 papers to 281 papers). Conclusions: Published papers on intervention for Urolithiasis have risen over the last 16 years. While there has been a steep rise of URS and minimally invasive PCNL techniques, SWL and open surgery have shown a slight decline over this period. A similar increase has also been seen for the use of simulation and lasers in Endourology. [ABSTRACT FROM AUTHOR]

Interactive computer simulations are commonly used as pedagogical tools to support students' statistical reasoning. This paper examines whether and how these simulations enable their intended effects. We begin by contrasting two theoretical frameworks—dual processes and grounded cognition—in the context of people's conceptions about statistical sampling, setting the stage for the potential benefits of simulations in learning such conceptions. Then, we continue with reviewing the educational literature on statistical sampling simulations. Our review tentatively suggests benefits of the simulations for building statistical habits of mind. However, challenges seem to persist when more specific concepts and skills are investigated. With and without simulations, students have difficulty forming an aggregate view of data, interpreting sampling distributions, showing a process-based understanding of the law of large numbers, making statistical inferences, and context-independent reasoning. We propose that grounded cognition offers a framework for understanding these findings, highlighting the bidirectional relationship between perception and conception, perceptual design features, and guided perceptual routines for supporting students' meaning making from simulations. Finally, we propose testable instructional strategies for using simulations in statistics education. Significance: Interactive computer simulations are popularly used to teach statistical sampling and inference. A substantial body of classroom-based design research has emerged over the last two decades on this topic, paralleling the interest of cognitive psychologists in statistical reasoning. This review bridges the gap by synthesizing diverse literature, from laboratory-based cognitive research to classroom-based design research, to investigate people's reasoning about statistical sampling with interactive computer simulations. We organize the commonly occurring findings from these studies under a grounded cognition framework. Using this framework, we also identify instructional design strategies that future empirical researchers can test and statistics and data science practitioners can adopt. First, we highlight the importance of repeated exposure to simulations in a way that fosters creating perception–action routines aligned with mathematical principles. Second, we argue that intuitive representations ground students' meaning making from simulations, and idealized representations help generalize learning. Third, we recommend that visual routines be guided during activities with simulations. Fourth, we note the separate affordances of simulations and verbal materials. Lastly, we propose that statistical processes depicted in the simulations should be reified as foundations for more advanced concepts and practices. Overall, the paper contributes to the learning theories and instructional design in the context of simulation-based learning in statistics. [ABSTRACT FROM AUTHOR]

Accurate and rapid prediction of the pipeline water hammer process is beneficial to the design and operation of the pipeline system. This paper proposed an accurate and efficient wave tracking method (EWTM) for the numerical simulation of water hammer in pipeline system. The proposed EWTM was developed based on the unsteady friction model and a new implementation scheme, which is combined with the Lagrangian scheme and the Eulerian scheme. The wave propagation equations of reservoir, valve and discrete vapor cavity model (DVCM) were also derived. To evaluate the performance of the EWTM, the single-phase water hammer and the two-phase water hammer were calculated with the EWTM and compared with the method of characteristic (MOC) and the experimental data. The evaluation result shows that EWTM has the same calculation accuracy as MOC, and the proposed EWTM method is over 90% more efficient than the MOC, which addresses the accuracy and efficiency limitations of the conventional wave tracking method (WTM).This paper provides a new idea on the improvement of simulation procedures and efficiency, which can be used for rapid calculation of transient flow in complex pipelines and for fault diagnosis which requires the highest numerical simulation accuracy. [ABSTRACT FROM AUTHOR]

This paper compares the interior spaces of the Great Halls of four Roman baths (Diocletian, Constantine, Caracalla and Agrippa), as documented in Palladio's reconstruction drawings, to the interior space of the nave of his Venetian church, Il Redentore. Three-dimensional computer models based on these reconstruction drawings then are compared to 3D computer models of the Il Redentore nave and side chapels. An interactive interface provides fresh insight into the architect's previously unexamined late design processes, and allows viewers to compare similarities in composition, form, and proportion by overlaying plan, sections and scaled 3D models of the bath's Great Halls and the Il Redentore interior. While it is well known that the design of Palladio's buildings, particularly his villas, drew many of their features from Roman architecture, this paper analyzes the design sources for the Il Redentore nave and side chapels and finds previously uninvestigated similarities in their form, composition, and proportions to the Great Halls of the Roman baths that a young, aspiring architect carefully documented, then studied closely. [ABSTRACT FROM AUTHOR]

During drilling operations, naturally, fractured formations are prone to show serious mud losses, which hinder drilling and increase nonproductive time and costs. The influencing factors of dynamic fluid loss are important for optimizing drilling parameters, reducing drilling fluid loss, and protecting oil and gas reservoirs. In this study, we simulated the dynamic filtration loss of drilling fluid during drilling under formation conditions using commercial software CMG (Computer Modelling Group). The effects of filtration time, filtrate viscosity, pressure difference, internal filter cake permeability, and external filter cake permeability on filtration loss were investigated. The simulation results showed that the permeability of the external mud cake is an important factor to control the fluid loss, and the pressure consumed by the external mud cake with low permeability can account for more than 90% of the total pressure difference. When the permeability of the external mud cake is high, the permeability of the internal mud cake also has a significant influence on the dynamic fluid loss. Under formation conditions, the dynamic fluid loss of radial fluid loss is still proportional to the filtration time and pressure difference, and inversely proportional to the filtrate viscosity of drilling fluid. Under the simulated conditions, the pressure will quickly transfer to the boundary, and the formation pressure at the same position in the formation will gradually increase, while the increase is relatively small with a constant filtration rate. The results of this paper can be used to the real site for drilling optimization. This numerical analysis method can be easily applied to filtrate loss analysis, formation damage area calculation, and other radial flow-related study. [ABSTRACT FROM AUTHOR]

This paper presents results of development of a numerical model of Lagrangian particle transport, as well as results of application of parallel computation methods to improve the efficiency of the software implementation of this model. The model is a software package that allows the transport and deposition of aerosol particles to be calculated taking into account properties of particles and the input data that describe atmospheric conditions and underlying surface geometry. The dynamic core, physical parameterizations, numerical implementation, and algorithm of the model are described. Results of successful verification of the model on analytical solutions are presented. Initially, the model was used for less computationally intensive problems. In this paper, given the need to use the model in more computationally intensive problems, we optimize the sequential software implementation of the model, as well as develop its software implementations that use parallel computing technologies (OpenMP, MPI, and CUDA). The results of testing different implementations of the model show that the optimization of the most computationally complex blocks in its sequential version can reduce the execution time by 27%. At the same time, the use of parallel computing technologies allows us to achieve acceleration by several orders of magnitude. The use of OpenMP in the dynamic block of the model provides almost 4-fold acceleration of this block; the use of MPI, almost 8-fold acceleration; and the use of CUDA, almost 16-fold acceleration (all other conditions being equal). We also give some recommendations on the choice of a parallel computing technology depending on the properties of a computing system. [ABSTRACT FROM AUTHOR]

Objective: This paper addresses the Graeco-Latin square design (GLSD) under neutrosophic statistics. In this work, we propose a novel approach for analyzing Graeco-Latin square designs using uncertain observations. Method: This approach involves the determination of a neutrosophic ANOVA and the determination of the neutrosophic hypotheses and decision rule. Results: The performance of the proposed design is evaluated using the numerical examples and simulation study. Conclusion: Based on the results observed, it can be concluded that the GLSD under neutrosophic statistics performs better than the GLSD under classical statistics in the presence of uncertainty. [ABSTRACT FROM AUTHOR]

Burden is one of the most important parameter which plays an immense role in rock breakage using explosive energy. It is very difficult to select the optimum burden under different geotechnical and geomining condition. The selection becomes more critical when the excavation method is underground as very few researches or studies have been carried out in such cases. Therefore, in this paper, numerical simulation-based approach has been employed to estimate the optimum burden for ring blasting. The numerical models were created under different scenario including blasthole diameter and strength of the rock. The RHT concrete constitutive model has been used in this paper to study the damage contour under different circumstances. The model output has been used to calculate the volume of rock damage along the free face. This damage volume is further correlated with various parameters. This correlation shows that the damage volume along the free face initially rises with the increase in burden and then starts decreasing after a certain value. The burden value which recorded the maximum volume of rock excavated along the free face has been considered as the optimum burden in this paper. The trial blast has been also carried out at the experimental site for twenty-four rings. The optimum burden achieved from the experimental trial for 102 mm blasthole diameter and rock having uniaxial compressive strength as 92 MPa lies between 2.4 and 2.65 m. However, the optimum burden predicted through developed empirical equation from the numerical model is 2.6 m. The study shows that the simulation-based prediction exhibits a minor deviation within 15% with the experimental result. Hence, to assess the optimum burden under various geotechnical and geomining circumstances, numerical simulation-based approach may be carried out using the proposed methodology. Highlights: Burden for ring blasting is optimised using different numerical simulation models. Volume of rock excavated along free face (EV) has been calculated in each case. The optimum burden from experimental trial and empirical data is 2.4–2.65 m. The optimum burden predicted from developed model is 2.6 m. [ABSTRACT FROM AUTHOR]

Over 90% of Australia's surfaced roads are unbound pavements with sprayed seals. However, achieving complete impermeability with these seals is challenging, leading to some moisture exchange between pavement layers and the environment. As moisture fluctuations influenced by climatic factors significantly affect the structural performance of particularly unbound granular layers, there is a pressing need to enhance Australian pavement design by incorporating climatic effects to meet better pavement performance. Hence, the current study numerically evaluates the degree of moisture saturation ( S r) variations of pavement layers under different Australian climates. This paper reveals how ambient climate impacts the moisture variations of pavement layers based on the results of 126 numerical simulations performed. Results indicated that the annual rainfall is not an appropriate parameter to decide the service moisture condition of the UGM layer, but the ratio between annual rainfall and annual pan evaporation ( P PE ) combined with the saturated permeability of the seal ( K s) is found to be a better indicator. More importantly, this study develops a novel empirical model to predict the service moisture condition of the UGM layers aiming to advance the current Australian pavement design guide. Furthermore, a correlation between pavement moisture and a widely used climatic index, Thornthwaite Moisture Index (TMI ) is presented in this study. Furthermore, this paper proposes a novel approach to integrating climatic factors into the current Australian pavement design of unbound pavements with thin seals. This study enhances understanding of the complex relationship between climate and pavement moisture by taking a multi-dimensional approach. [ABSTRACT FROM AUTHOR]

With the shift of coal seam mining to the deep, the in-situ stress of coal and rock mass increases gradually. High ground stress can limit the generation of rock cracks caused by blasting, and blasting usually shows different crushing states than low stress conditions. In order to study the blasting expansion rule of rock mass with cavity under high ground stress and the rock mass fracture state under different side stress coefficients. In this paper, the effective range of blasting and the stress distribution under blasting load are analyzed theoretically. The RHT (Riedel-Hiermaier-Thoma) model is used to numerically simulate the blasting process of rock mass with cavity under different ground stress, and the influence of ground stress and lateral pressure coefficient on the crack growth of rock mass is studied. The results show that when there is no ground stress, the damage cracks in rock mass are more concentrated in the horizontal direction and the fracture development tends to the direction where the holes are located, which confirms the guiding effect and stress concentration effect of the holes in rock mass, which helps to promote the crack penetration between the hole and the hole. The length difference of horizontal and vertical damage cracks in rock mass increases with the increase of horizontal and vertical stress difference. Under the same lateral stress coefficient, the larger the horizontal and vertical stress difference is, the stronger the inhibition effect on crack formation is. For blasting of rock mass with high ground stress, the crack formation length between gun holes decreases with the increase of stress level, and the crack extends preferentially in the direction of higher stress. Therefore, the placement of gun holes along the direction of greater stress and the shortening of hole spacing are conducive to the penetration of cracks between gun holes and empty holes. The research can provide reference for rock breaking behavior of deep rock mass blasting. [ABSTRACT FROM AUTHOR]

In the present paper the high-frequency induction welding process is studied numerically. The mathematical model comprises a harmonic vector potential formulation of the Maxwell equations and a quasi-static, convection dominated heat equation coupled through the Joule heat term and nonlinear constitutive relations. Its main novelties are a new analytic approach which permits to compute a spatially varying feed velocity depending on the angle of the Vee-opening and additional spring-back effects. Moreover, a numerical stabilization approach for the finite element discretization allows to consider realistic weld-line speeds and thus a fairly comprehensive three-dimensional simulation of the tube welding process. [ABSTRACT FROM AUTHOR]

Micro-mixers and piezoelectric pumps have been studied as independent parts, which achieves only single mixing or pumping functions. A new valveless piezoelectric mixing pump (VPMP) driven by a sinusoidal signal is proposed in this paper to achieve a structure with both pumping and mixing functions. It accomplishes this by placing obstacles in the pump chamber and in the flow channel then adding active mixing. Because it is small in size, has a simple structure and is easy to control, it can be used in micro mixing applications. In this study, numerical simulation analysis using the Fluent software tests if the new VPMP has good mixing and pumping performance, and analyzes the effect of the obstacles. Simultaneously, the results of numerical simulation are verified with experiments. It was proven that the flow rate of the VPMP can reach 12.26 mL/min, and that the liquid can achieve uniform mixing. Moreover, the obstacle placed in the pump chamber has a more obvious impact on the mixing capability, and the obstacle placed in the channel has a more obvious impact on the flow rate. In addition, with the increase of the amplitude of driving signal, the flow rate of the VPMP increased correspondingly. With the increase of the frequency, the flow rate first increased and then decreased. The capability of mixing increased with an increase of working frequency. The experimental results showed that the VPMP can achieve good pumping and mixing performance, and that one structure can possess both mixing and pumping functions. [ABSTRACT FROM AUTHOR]

In recent decades, interest in simulation modeling of plasma processing under atmospheric pressure has been growing because of its appealing advantages across various domains. These advantages encompass the provision of diverse data types for evaluating processing states, the capability to predict processing outcomes from current operating conditions, and cost-effectiveness in comparison to experimental methods. This paper endeavors to offer a concise review of the evolution of simulation modeling of atmospheric plasma processing. This review encompasses foundational concepts and methodologies of plasma generation modeling of both thermal and nonthermal plasmas, progressing to discuss the framework and challenges of plasma processing modeling. In addition, a brief overview of contemporary challenges in modeling, such as simplifying complex physics, designing computational domains, and optimizing the balance between computational precision and cost, is provided to foster the advancement of atmospheric plasma processing modeling. Highlights: Classification and simulation modeling methodology of well-known atmospheric pressure plasma generation methods. Features and current challenges of some widely applied plasma processing techniques. Framework of current plasma processing simulation models and clarification of existing challenges and related solutions. [ABSTRACT FROM AUTHOR]

This paper is based on the proximity engineering project of the Baishiyi tunnel group passing under the Chongqing West Station track group. Considering the train load and the spatial relationship of the tunnel and track groups, the settlement patterns, horizontal displacement, and differential settlement of the tunnel–strata–tracks system during the excavation process are studied through theoretical calculations and numerical simulation methods. The results indicate that the tunnel vault, strata, and track settlement deformation patterns are similar. Throughout the tunnel construction process, the tracks underwent uplift, settlement, and eventually stabilized. The settlement trough formed by the excavation of the three tunnels below the track group has an impact range of 25–145 m. Between 35 and 75 m, the differential settlement of the double track gradually increases with excavation. As the tunnel face reaches 75 m, the track differential settlement gradually converges and tends to stabilize. To minimize the impact of underpass tunnel construction on track groups, it is recommended to use a combination of full-section hole grouting and surface reinforcement grouting for ground reinforcement. Additionally, optimizing the construction parameters, including the step length and primary support closure time, and strengthening the locking anchor can further reduce the impact. [ABSTRACT FROM AUTHOR]

In this paper, the effects of different designs of pressure vessels on hydrodynamic parameters and the performance of seawater RO systems are investigated using computer simulations. Simulation results showed that designs using pressure vessels with four membranes in two-pass RO systems have a lower energy consumption, 5.29 and 0.33 kWh/m3 for the first and second passes, respectively, than those with two or three membranes. Also, designs No. 4 and No. 10 were the most efficient, 41 and 56% for the first and second passes, respectively, compared to other ones. The first and second passes required a lower permeate and feed pressure when using designs No. 3, No. 6, No. 9, and No. 12 where pressure vessels with two membranes were used. In addition, hybrid designs of two-pass RO systems were found to have the best efficiency and the lowest energy consumption among various other designs. Findings showed that in two-pass RO systems, the first pass consumes more energy than the second pass. Thus, the efficiency of the second pass in all designs of two-pass RO systems is more than the first pass. The results presented in this paper can be used to optimize the design of two-pass RO systems to ensure the optimum operation of such systems. [ABSTRACT FROM AUTHOR]

This paper is devoted to the study of spatio-temporal dynamics for a time-space periodic population growth model with impulsive birth. We first formulate a discrete-time semiflow by the 1-year solution map, and obtain a threshold-type result for the semiflow with spatially periodic initial data. Then we establish the existence and the computational formulas of the spreading speeds and prove the coincidence of the spreading speeds with the minimal speeds of spatially periodic traveling waves in the monotone case. Further, we investigate the global dynamics of this model in a bounded spatial domain. Finally, we conduct numerical simulations to verify our analytical results and illustrate some interesting findings. [ABSTRACT FROM AUTHOR]

Over the years, researchers have proposed models for analyzing and predicting the low-frequency behavior of wind farm grounding systems. The lumped parameter modeling based on circuit theory presents an acceptable compromise between ease of implementation, consumption of computational resources, and accuracy of the results. This paper addresses the impact of mutual couplings between grounding elements in measuring the wind turbines grounding impedance using a clamp-on-ground meter. Furthermore, it proposes a new lumped parameter model for wind farm grounding to include the representation of such effects. In this study, computer simulation uses lumped parameter modeling and electromagnetic field modeling to evaluate turbine grounding impedance readings based on actual wind farm project data. The simulation results, assuming the electromagnetic model as a reference, have demonstrated that the proposed solution can estimate the low-frequency impedance of the measuring loop with an average error of 85.8% lower than existing state-of-the-art models. [ABSTRACT FROM AUTHOR]

In this paper, a stochastic non-autonomous chemostat model with mean-reverting Ornstein–Uhlenbeck process is constructed and analyzed, and we consider the stochastic perturbation on the washout rate. We first study the existence of global unique positive solution and stochastically ultimate boundedness for new stochastic chemostat system. Secondly, we obtain that the sufficient conditions for extinction exponentially and stochastic permanence of microorganism. Finally, we also give some numerical simulations, which show that the mean-reverting Ornstein–Uhlenbeck process is a very effective and reasonable method to introduce environmental noise into the chemostat model, and we also find that the reversion speed and volatility intensity have an important influence on the dynamical behavior of microorganism. [ABSTRACT FROM AUTHOR]

Planar erosion is an important mode of soil erosion, which occurs in the process of loess slope erosion, gully erosion, and cave erosion. It is of great significance to understand the characteristics and mechanism of planar erosion to reveal the mechanism of loess erosion and the prevention and treatment of soil and water loss. In this paper, a series of loess planar erosion tests have been carried out through self-developed large-scale loess scour instrument. The erosion process and stage characteristics of subsurface erosion under different conditions have been analyzed and summarized, and the internal mechanism of the loess planar erosion process in different erosion characteristic stages has been revealed. Furthermore, based on the special "core (powder) + coat" microstructure characteristics of loess, a numerical model of inter particle linkage was established to characterize the characteristics of loess microstructure and anti-erosion properties. The numerical simulation results carried out based on the numerical model of inter particle linkage established in this paper are in good agreement with the main results of the physical simulation of planar erosion. The results all show that the loess planar erosion at the scale of large test blocks can be divided into three characteristic stages: uniform planar erosion stage, micro gully erosion stage, and collapse failure stage. This indicates that the fluid–solid coupling simulation method of CFD–DEM proposed in this paper has high simulation accuracy and has great application potential in the research and application of loess erosion. This provides a new and feasible idea for the study of loess slope erosion and hydraulic loss control on the Loess Plateau, which is worthy of further promotion. [ABSTRACT FROM AUTHOR]

The shale oil reservoirs of the Lucaogou Formation in the Jimsar Sag developed a large number of natural fractures and thin interlayers. The expansion of hydraulic fractures is full of randomness and unknowingness due to this complex geological feature. Since the multi-cluster fracturing process with small well spacing is widely used, the growth of hydraulic fractures requires a combined consideration of competition between perforation clusters and interference between wells. From the perspective of engineering application, this paper summarizes the fracture propagation law under single-fracture, multi-cluster fracturing, and adjacent well interference from simple to complex based on three-dimensional discrete element methods and a large number of field data. Then the key controlling factors of fracture group morphology were quantitatively analyzed. Comparative analysis reveals that under complex geological conditions, a single crack can still be described by existing theories, but the expansion law of the fracture group is not a simple superposition of single fractures. The competitive expansion of multiple fractures is reflected in the Fracture Surface Area (FSA) differences between clusters, asymmetry, and irregularity. Moreover, under inter-well stress interference, the hydraulic fractures of the posterior-construction well will tend to expand in the opposite direction of the first-construction well. The optimal well spacing of the Jimsar shale oil reservoir is 200–300 m. Highlights: In this paper, there are five highlights worthy of attention: This paper discussed the fracture propagation law under actual multi-cluster fracturing conditions through three aspects: 1. Clarifying the difference between the expansion law of multi-fracture competition and traditional cognition by comparing the morphology of fracture group and single-fracture; 2. Competitive expansion modes were quantitatively analyzed through FSA curves and inter-cluster stress interference. 3. Based on inter-well stress interference, a more complex simulation of actual working conditions was carried out to elaborate further on the influence of inter-well stress interference on fracture expansion. This paper compared the penetration expansion ability of hydraulic fractures under the condition of single fractures and fracture group. We quantitatively analyzed the dynamic characteristics of multi-fracture competitive expansion through Fracture Surface Area (FSA) and evaluated the morphological attributes of fracture groups under inter-cluster and inter-well stress interference. The stress interference range and the increment of the minimum horizontal in situ stress caused by fracturing adjacent well under different well spacings were quantitatively analyzed. The research was based entirely on the actual working conditions of the oil field, and the microseismic data and simulation results were thoroughly compared and demonstrated, which ensured the reliability of the conclusions. [ABSTRACT FROM AUTHOR]

This article presents and investigates a modified version of the Weibull distribution that incorporates four parameters and can effectively represent a hazard rate function with a shape resembling a bathtub. Its significance in the fields of lifetime and reliability stems from its ability to model both increasing and decreasing failure rates. The proposed distribution encompasses several well-known models such as the Weibull, extreme value, exponentiated Weibull, generalized Rayleigh, and modified Weibull distributions. The paper derives key mathematical statistics of the proposed distribution, including the quantile function, moments, moment-generating function, and order statistics density. Various mathematical properties of the proposed model are established, and the unknown parameters of the distribution are estimated using different estimation techniques. Furthermore, the effectiveness of these estimators is assessed through numerical simulation studies. Finally, the paper applies the new model and compares it with various existing distributions by analyzing two real-life time data sets. [ABSTRACT FROM AUTHOR]

The present work is a numerical follow-up on our published experimental paper on shock ignition of aluminium particle clouds in the low-temperature regime. The in-house multi-phase regularized smoothed particle hydrodynamics (MP-RSPH) code is used to perform numerical simulations with an increasing degree of complexity, looking at single-phase, inert, and reactive particles in separate simulations. The first part of the paper gives a short description of the additional physics added to the code. Based on the experimental results, the numerical code is then used to estimate the particle temperature at the time of ignition. Results from simulations with three different numerical descriptions, the diffusive, kinetic, and total burn rates, are then compared to the experimental results. The two diffusive burn rate simulations (K &H and O &H) show the best fit to the experimental results. The burn rate formula based on our experimental data (O &H) is preferred, since it has the gas temperature dependency included and does not require additional parameter adjustments. The results from the numerical simulations support the theory that the observed aluminium particle cloud burning process is diffusive, as indicated in the experimental paper. [ABSTRACT FROM AUTHOR]

In this paper, we present a network-based optimization model describing a closed-loop supply chain for the provision of 5G network slices on demand to users and devices on the ground. The three-tier supply chain network consists of a fleet of pre-existing UAVs, to which others can be added, managed by a fleet of UAV controllers, whose purpose is to perform services requested by users and devices on the ground. The aim of this paper is to provide a constrained optimization problem through which the providers' profits are maximized, determining the global optimal distributions of request flows, the global optimal distributions of executed services and the optimal reliability level of pre-existing UAVs of the fleet. We also derive the associated Variational inequality formulation of the problem and, finally, a numerical simulation is performed to validate the effectiveness of the model. [ABSTRACT FROM AUTHOR]

Experience replay (ER) used in (deep) reinforcement learning is considered to be applicable only to off-policy algorithms. However, there have been some cases in which ER has been applied for on-policy algorithms, suggesting that off-policyness might be a sufficient condition for applying ER. This paper reconsiders more strict "experience replayable conditions" (ERC) and proposes the way of modifying the existing algorithms to satisfy ERC. In light of this, it is postulated that the instability of policy improvements represents a pivotal factor in ERC. The instability factors are revealed from the viewpoint of metric learning as i) repulsive forces from negative samples and ii) replays of inappropriate experiences. Accordingly, the corresponding stabilization tricks are derived. As a result, it is confirmed through numerical simulations that the proposed stabilization tricks make ER applicable to an advantage actor-critic, an on-policy algorithm. Moreover, its learning performance is comparable to that of a soft actor-critic, a state-of-the-art off-policy algorithm. [ABSTRACT FROM AUTHOR]

The nozzle structure parameters of a liquid-gas ejector have an important effect on the performance of the ejector. In this paper, a numerical simulation model of a liquid-gas ejector was developed. To optimize the gas induction and mixing performance of the ejector, the effect of the nozzle structure on the flow mixing characteristics inside the liquid-gas ejector is investigated. The rationality of the numerical simulation was verified by using the experimental equipment, and the maximum relative error between the experimental and simulated data was 9.72%, which proved the reliability of the numerical simulation. The results show that: conical, folded line, and arc-shaped three different shapes of the nozzle, which the conical nozzle has the best ability to induct gas. The injection coefficient will decrease gradually with the increase of nozzle length, and the injection coefficient will increase with the increase of nozzle outlet straight section length, etc. The research results of this paper can be used to improve the gas induction and mixing performance of the liquid-gas ejector, and play an important guiding role in the design optimization of the ejector. [ABSTRACT FROM AUTHOR]

The aim of this paper is to review the literature in the field of supplier selection under supply chain risk management. Collected papers from 2003 to 2014 are analyzed and classified, first, according to the characteristics of the problem they deal with, secondly, according to the approach they propose, and thirdly, according to the techniques they use. The papers have been grouped into five categories: the first group relates to quantitative approaches to supplier selection, the second concerns qualitative approaches, the third consists of hybrid approaches that blend two or more different approaches together, the fourth relates to simulation approaches and the last group to artificial intelligence. The techniques used in each category are outlined. The different approaches and their associated techniques are analyzed and some recommendations are made on improving their efficiency and performance. This paper is thus a systematic scope review of journal articles and conference papers issued during this period. It brings together a collection of 124 papers on the topic of supplier selection under supply chain risk management. [ABSTRACT FROM AUTHOR]

The goal of this paper is to use the finite element method and computer simulation to prove the effectiveness in assessing the fire resistance of building construction elements, specifically on the example of the fire resistance of fire doors. For that purpose, data from the building where fire doors with defined characteristics were installed were used. For simulation purposes, numerical modelling with thermal and structural analysis will be used. In this way, the parameters of the temperature distribution on the fire door and the contact material due to fire will be obtained, as well as the distribution of strain and stresses, which will indicate the fire resistance of the used structure. Computer simulation with numerical modelling offers a number of advantages both in the speed of providing results of a larger number of variants of the simulation model and in the accuracy of the results obtained once the model is calibrated. Also, the mentioned type of predicting the effect of fire can be applied to other elements of the structure of the construction object, which can significantly influence the decision-making that will prevent the negative consequences of the occurrence of a possible fire. [ABSTRACT FROM AUTHOR]

Several real-life problems that involve a time delay are modeled using fractional time-delay systems. However, most studies related to these systems assume that the delay is already known, which is not the case in practical scenarios where the delay is often uncertain or unknown. To address this issue, this paper proposes an algebraic and robust method to estimate the input delay for a class of fractional time-delay systems in a noisy environment, by applying a cross-convolution approach. Besides, a filtering methodology is incorporated with the proposed approach to enhance its efficacy. In addition, this paper presents novel theories on convolution in the field of fractional calculus. Finally, the performance of the proposed approach is demonstrated by numerical simulations. [ABSTRACT FROM AUTHOR]

This paper presents general theoretical studies on asymptotic convergence rate (ACR) for finite dimensional optimization. Given the continuous problem function and discrete time stochastic optimization process, the ACR is the optimal constant for control of the asymptotic behaviour of the expected approximation errors. Under general assumptions, condition ACR < 1 implies the linear behaviour of the expected time of hitting the ε - optimal sublevel set with ε → 0 + and determines the upper bound for the convergence rate of the trajectories of the process. This paper provides general characterization of ACR and, in particular, shows that some algorithms cannot converge linearly fast for any nontrivial continuous optimization problem. The relation between asymptotic convergence rate in the objective space and asymptotic convergence rate in the search space is provided. Examples and numerical simulations with use of a (1+1) self-adaptive evolution strategy and other algorithms are presented. [ABSTRACT FROM AUTHOR]

In the case of multicollinearity, biased estimators are always introduced to correct the least squares estimator. In this paper, we propose a new biased estimator for the restricted linear model. The properties of the new estimator and its superiority over the restricted least squares estimator in terms of the mean square error and Pitman closeness criterion are theoretically analysed. Furthermore, we optimize and verify the feasibility of the new estimator using a numerical simulation. [ABSTRACT FROM AUTHOR]

Background: Shortages of mechanical ventilation have become a constant problem in Emergency Departments (EDs), thereby affecting the timely deployment of medical interventions that counteract the severe health complications experienced during respiratory disease seasons. It is then necessary to count on agile and robust methodological approaches predicting the expected demand loads to EDs while supporting the timely allocation of ventilators. In this paper, we propose an integration of Artificial Intelligence (AI) and Discrete-event Simulation (DES) to design effective interventions ensuring the high availability of ventilators for patients needing these devices. Methods: First, we applied Random Forest (RF) to estimate the mechanical ventilation probability of respiratory-affected patients entering the emergency wards. Second, we introduced the RF predictions into a DES model to diagnose the response of EDs in terms of mechanical ventilator availability. Lately, we pretested two different interventions suggested by decision-makers to address the scarcity of this resource. A case study in a European hospital group was used to validate the proposed methodology. Results: The number of patients in the training cohort was 734, while the test group comprised 315. The sensitivity of the AI model was 93.08% (95% confidence interval, [88.46 − 96.26%]), whilst the specificity was 85.45% [77.45 − 91.45%]. On the other hand, the positive and negative predictive values were 91.62% (86.75 − 95.13%) and 87.85% (80.12 − 93.36%). Also, the Receiver Operator Characteristic (ROC) curve plot was 95.00% (89.25 − 100%). Finally, the median waiting time for mechanical ventilation was decreased by 17.48% after implementing a new resource capacity strategy. Conclusions: Combining AI and DES helps healthcare decision-makers to elucidate interventions shortening the waiting times for mechanical ventilators in EDs during respiratory disease epidemics and pandemics. [ABSTRACT FROM AUTHOR]